v3.26.1
Shareholder Report
 6 Months Ended
Mar. 31, 2026
USD ($)
Holding
Shareholder Report [Line Items]  
Document Type N-CSRS
Amendment Flag false
Registrant Name LORD ABBETT MUNICIPAL INCOME FUND INC
Entity Central Index Key 0000737800
Entity Investment Company Type N-1A
Document Period End Date Mar. 31, 2026
Shareholder Report Annual or Semi-Annual Semi-Annual Shareholder Report
C000096621  
Shareholder Report [Line Items]  
Fund Name Lord Abbett High Income Municipal Bond Fund
Class Name Class A
Trading Symbol HYMAX
Annual or Semi-Annual Statement [Text Block] This semi-annual shareholder report contains important information about the Lord Abbett High Income Municipal Bond Fund for the period of October 1, 2025 to March 31, 2026.
Additional Information [Text Block] You can find additional information about the Fund at lordabbett.com/FundDocuments. You can also request this information by contacting us at 888-522-2388.
Additional Information Phone Number 888-522-2388
Additional Information Website <span style="box-sizing: border-box; color: rgb(0, 0, 0); display: inline; flex-wrap: nowrap; font-size: 13.3333px; font-weight: 400; grid-area: auto; line-height: 20px; margin: 0px; overflow: visible; text-align: left; text-align-last: auto; white-space-collapse: preserve-breaks;">lordabbett.com/FundDocuments</span>
Expenses [Text Block]

What were the Fund costs for the last period?

(based on a hypothetical $10,000 investment)

Table Summary
Class Name
Costs of a $10,000 investment
Costs paid as a percentage of a $10,000 investment
Class A
$44
0.87%Footnote Reference(a)
FootnoteDescription
Footnote(a)
Annualized.
Expenses Paid, Amount $ 44
Expense Ratio, Percent 0.87% [1]
AssetsNet $ 4,355,247,183
Holdings Count | Holding 603
InvestmentCompanyPortfolioTurnover 10.00%
Additional Fund Statistics [Text Block]

Key Fund Statistics

 

 (as of March 31, 2026)

Table Summary
Total Net Assets
$4,355,247,183
# of Portfolio Holdings
603
Portfolio Turnover Rate
10%
Holdings [Text Block]
Table Summary
Portfolio Holdings Presented by Credit Rating S&P or Moody'sFootnote Reference*
%Footnote Reference**
  • A4.19%
  • A-0.67%
  • A+2.54%
  • AA3.91%
  • AA-1.94%
  • AA+0.95%
  • AAA0.84%
  • B1.03%
  • B-2.10%
  • B+1.53%
  • BB2.09%
  • BB-0.64%
  • BB+13.21%
  • BBB4.81%
  • BBB-9.95%
  • BBB+1.61%
  • CC0.12%
  • CCC0.34%
  • CCC-0.80%
  • CCC+0.25%
  • NR46.48%
  • Total 100.00%
FootnoteDescription
Footnote*
Investments in investment grade municipal bonds, which are bonds that are rated, at the time of purchase, within the four highest grades assigned by an independent rating agency such as Moody’s, S&P, or Fitch, or an equivalent short-term rating, as applicable, or are unrated by rating agencies but deemed by Lord Abbett to be of comparable quality. Lower rated municipal bonds are rated, at the time of purchase, or an equivalent short-term rating, as applicable, by an independent rating agency or are unrated by rating agencies but deemed by Lord Abbett to be of comparable quality.
Footnote**
Represents percent of total investments, which excludes derivatives.
Credit Ratings Selection [Text Block] Investments in investment grade municipal bonds, which are bonds that are rated, at the time of purchase, within the four highest grades assigned by an independent rating agency such as Moody’s, S&P, or Fitch, or an equivalent short-term rating, as applicable, or are unrated by rating agencies but deemed by Lord Abbett to be of comparable quality. Lower rated municipal bonds are rated, at the time of purchase, or an equivalent short-term rating, as applicable, by an independent rating agency or are unrated by rating agencies but deemed by Lord Abbett to be of comparable quality.
C000096623  
Shareholder Report [Line Items]  
Fund Name Lord Abbett High Income Municipal Bond Fund
Class Name Class C
Trading Symbol HYMCX
Annual or Semi-Annual Statement [Text Block] This semi-annual shareholder report contains important information about the Lord Abbett High Income Municipal Bond Fund for the period of October 1, 2025 to March 31, 2026.
Additional Information [Text Block] You can find additional information about the Fund at lordabbett.com/FundDocuments. You can also request this information by contacting us at 888-522-2388.
Additional Information Phone Number 888-522-2388
Additional Information Website <span style="box-sizing: border-box; color: rgb(0, 0, 0); display: inline; flex-wrap: nowrap; font-size: 13.3333px; font-weight: 400; grid-area: auto; line-height: 20px; margin: 0px; overflow: visible; text-align: left; text-align-last: auto; white-space-collapse: preserve-breaks;">lordabbett.com/FundDocuments</span>
Expenses [Text Block]

What were the Fund costs for the last period?

(based on a hypothetical $10,000 investment)

Table Summary
Class Name
Costs of a $10,000 investment
Costs paid as a percentage of a $10,000 investment
Class C
$75
1.50%Footnote Reference(a)
FootnoteDescription
Footnote(a)
Annualized.
Expenses Paid, Amount $ 75
Expense Ratio, Percent 1.50% [2]
AssetsNet $ 4,355,247,183
Holdings Count | Holding 603
InvestmentCompanyPortfolioTurnover 10.00%
Additional Fund Statistics [Text Block]

Key Fund Statistics

 

 (as of March 31, 2026)

Table Summary
Total Net Assets
$4,355,247,183
# of Portfolio Holdings
603
Portfolio Turnover Rate
10%
Holdings [Text Block]
Table Summary
Portfolio Holdings Presented by Credit Rating S&P or Moody'sFootnote Reference*
%Footnote Reference**
  • A4.19%
  • A-0.67%
  • A+2.54%
  • AA3.91%
  • AA-1.94%
  • AA+0.95%
  • AAA0.84%
  • B1.03%
  • B-2.10%
  • B+1.53%
  • BB2.09%
  • BB-0.64%
  • BB+13.21%
  • BBB4.81%
  • BBB-9.95%
  • BBB+1.61%
  • CC0.12%
  • CCC0.34%
  • CCC-0.80%
  • CCC+0.25%
  • NR46.48%
  • Total 100.00%
FootnoteDescription
Footnote*
Investments in investment grade municipal bonds, which are bonds that are rated, at the time of purchase, within the four highest grades assigned by an independent rating agency such as Moody’s, S&P, or Fitch, or an equivalent short-term rating, as applicable, or are unrated by rating agencies but deemed by Lord Abbett to be of comparable quality. Lower rated municipal bonds are rated, at the time of purchase, or an equivalent short-term rating, as applicable, by an independent rating agency or are unrated by rating agencies but deemed by Lord Abbett to be of comparable quality.
Footnote**
Represents percent of total investments, which excludes derivatives.
Credit Ratings Selection [Text Block] Investments in investment grade municipal bonds, which are bonds that are rated, at the time of purchase, within the four highest grades assigned by an independent rating agency such as Moody’s, S&P, or Fitch, or an equivalent short-term rating, as applicable, or are unrated by rating agencies but deemed by Lord Abbett to be of comparable quality. Lower rated municipal bonds are rated, at the time of purchase, or an equivalent short-term rating, as applicable, by an independent rating agency or are unrated by rating agencies but deemed by Lord Abbett to be of comparable quality.
C000096624  
Shareholder Report [Line Items]  
Fund Name Lord Abbett High Income Municipal Bond Fund
Class Name Class F
Trading Symbol HYMFX
Annual or Semi-Annual Statement [Text Block] This semi-annual shareholder report contains important information about the Lord Abbett High Income Municipal Bond Fund for the period of October 1, 2025 to March 31, 2026.
Additional Information [Text Block] You can find additional information about the Fund at lordabbett.com/FundDocuments. You can also request this information by contacting us at 888-522-2388.
Additional Information Phone Number 888-522-2388
Additional Information Website <span style="box-sizing: border-box; color: rgb(0, 0, 0); display: inline; flex-wrap: nowrap; font-size: 13.3333px; font-weight: 400; grid-area: auto; line-height: 20px; margin: 0px; overflow: visible; text-align: left; text-align-last: auto; white-space-collapse: preserve-breaks;">lordabbett.com/FundDocuments</span>
Expenses [Text Block]

What were the Fund costs for the last period?

(based on a hypothetical $10,000 investment)

Table Summary
Class Name
Costs of a $10,000 investment
Costs paid as a percentage of a $10,000 investment
Class F
$39
0.77%Footnote Reference(a)
FootnoteDescription
Footnote(a)
Annualized.
Expenses Paid, Amount $ 39
Expense Ratio, Percent 0.77% [3]
AssetsNet $ 4,355,247,183
Holdings Count | Holding 603
InvestmentCompanyPortfolioTurnover 10.00%
Additional Fund Statistics [Text Block]

Key Fund Statistics

 

 (as of March 31, 2026)

Table Summary
Total Net Assets
$4,355,247,183
# of Portfolio Holdings
603
Portfolio Turnover Rate
10%
Holdings [Text Block]
Table Summary
Portfolio Holdings Presented by Credit Rating S&P or Moody'sFootnote Reference*
%Footnote Reference**
  • A4.19%
  • A-0.67%
  • A+2.54%
  • AA3.91%
  • AA-1.94%
  • AA+0.95%
  • AAA0.84%
  • B1.03%
  • B-2.10%
  • B+1.53%
  • BB2.09%
  • BB-0.64%
  • BB+13.21%
  • BBB4.81%
  • BBB-9.95%
  • BBB+1.61%
  • CC0.12%
  • CCC0.34%
  • CCC-0.80%
  • CCC+0.25%
  • NR46.48%
  • Total 100.00%
FootnoteDescription
Footnote*
Investments in investment grade municipal bonds, which are bonds that are rated, at the time of purchase, within the four highest grades assigned by an independent rating agency such as Moody’s, S&P, or Fitch, or an equivalent short-term rating, as applicable, or are unrated by rating agencies but deemed by Lord Abbett to be of comparable quality. Lower rated municipal bonds are rated, at the time of purchase, or an equivalent short-term rating, as applicable, by an independent rating agency or are unrated by rating agencies but deemed by Lord Abbett to be of comparable quality.
Footnote**
Represents percent of total investments, which excludes derivatives.
Credit Ratings Selection [Text Block] Investments in investment grade municipal bonds, which are bonds that are rated, at the time of purchase, within the four highest grades assigned by an independent rating agency such as Moody’s, S&P, or Fitch, or an equivalent short-term rating, as applicable, or are unrated by rating agencies but deemed by Lord Abbett to be of comparable quality. Lower rated municipal bonds are rated, at the time of purchase, or an equivalent short-term rating, as applicable, by an independent rating agency or are unrated by rating agencies but deemed by Lord Abbett to be of comparable quality.
C000188226  
Shareholder Report [Line Items]  
Fund Name Lord Abbett High Income Municipal Bond Fund
Class Name Class F3
Trading Symbol HYMOX
Annual or Semi-Annual Statement [Text Block] This semi-annual shareholder report contains important information about the Lord Abbett High Income Municipal Bond Fund for the period of October 1, 2025 to March 31, 2026.
Additional Information [Text Block] You can find additional information about the Fund at lordabbett.com/FundDocuments. You can also request this information by contacting us at 888-522-2388.
Additional Information Phone Number 888-522-2388
Additional Information Website <span style="box-sizing: border-box; color: rgb(0, 0, 0); display: inline; flex-wrap: nowrap; font-size: 13.3333px; font-weight: 400; grid-area: auto; line-height: 20px; margin: 0px; overflow: visible; text-align: left; text-align-last: auto; white-space-collapse: preserve-breaks;">lordabbett.com/FundDocuments</span>
Expenses [Text Block]

What were the Fund costs for the last period?

(based on a hypothetical $10,000 investment)

Table Summary
Class Name
Costs of a $10,000 investment
Costs paid as a percentage of a $10,000 investment
Class F3
$31
0.61%Footnote Reference(a)
FootnoteDescription
Footnote(a)
Annualized.
Expenses Paid, Amount $ 31
Expense Ratio, Percent 0.61% [4]
AssetsNet $ 4,355,247,183
Holdings Count | Holding 603
InvestmentCompanyPortfolioTurnover 10.00%
Additional Fund Statistics [Text Block]

Key Fund Statistics

 

 (as of March 31, 2026)

Table Summary
Total Net Assets
$4,355,247,183
# of Portfolio Holdings
603
Portfolio Turnover Rate
10%
Holdings [Text Block]
Table Summary
Portfolio Holdings Presented by Credit Rating S&P or Moody'sFootnote Reference*
%Footnote Reference**
  • A4.19%
  • A-0.67%
  • A+2.54%
  • AA3.91%
  • AA-1.94%
  • AA+0.95%
  • AAA0.84%
  • B1.03%
  • B-2.10%
  • B+1.53%
  • BB2.09%
  • BB-0.64%
  • BB+13.21%
  • BBB4.81%
  • BBB-9.95%
  • BBB+1.61%
  • CC0.12%
  • CCC0.34%
  • CCC-0.80%
  • CCC+0.25%
  • NR46.48%
  • Total 100.00%
FootnoteDescription
Footnote*
Investments in investment grade municipal bonds, which are bonds that are rated, at the time of purchase, within the four highest grades assigned by an independent rating agency such as Moody’s, S&P, or Fitch, or an equivalent short-term rating, as applicable, or are unrated by rating agencies but deemed by Lord Abbett to be of comparable quality. Lower rated municipal bonds are rated, at the time of purchase, or an equivalent short-term rating, as applicable, by an independent rating agency or are unrated by rating agencies but deemed by Lord Abbett to be of comparable quality.
Footnote**
Represents percent of total investments, which excludes derivatives.
Credit Ratings Selection [Text Block] Investments in investment grade municipal bonds, which are bonds that are rated, at the time of purchase, within the four highest grades assigned by an independent rating agency such as Moody’s, S&P, or Fitch, or an equivalent short-term rating, as applicable, or are unrated by rating agencies but deemed by Lord Abbett to be of comparable quality. Lower rated municipal bonds are rated, at the time of purchase, or an equivalent short-term rating, as applicable, by an independent rating agency or are unrated by rating agencies but deemed by Lord Abbett to be of comparable quality.
C000096625  
Shareholder Report [Line Items]  
Fund Name Lord Abbett High Income Municipal Bond Fund
Class Name Class I
Trading Symbol HYMIX
Annual or Semi-Annual Statement [Text Block] This semi-annual shareholder report contains important information about the Lord Abbett High Income Municipal Bond Fund for the period of October 1, 2025 to March 31, 2026.
Additional Information [Text Block] You can find additional information about the Fund at lordabbett.com/FundDocuments. You can also request this information by contacting us at 888-522-2388.
Additional Information Phone Number 888-522-2388
Additional Information Website <span style="box-sizing: border-box; color: rgb(0, 0, 0); display: inline; flex-wrap: nowrap; font-size: 13.3333px; font-weight: 400; grid-area: auto; line-height: 20px; margin: 0px; overflow: visible; text-align: left; text-align-last: auto; white-space-collapse: preserve-breaks;">lordabbett.com/FundDocuments</span>
Expenses [Text Block]

What were the Fund costs for the last period?

(based on a hypothetical $10,000 investment)

Table Summary
Class Name
Costs of a $10,000 investment
Costs paid as a percentage of a $10,000 investment
Class I
$34
0.67%Footnote Reference(a)
FootnoteDescription
Footnote(a)
Annualized.
Expenses Paid, Amount $ 34
Expense Ratio, Percent 0.67% [5]
AssetsNet $ 4,355,247,183
Holdings Count | Holding 603
InvestmentCompanyPortfolioTurnover 10.00%
Additional Fund Statistics [Text Block]

Key Fund Statistics

 

 (as of March 31, 2026)

Table Summary
Total Net Assets
$4,355,247,183
# of Portfolio Holdings
603
Portfolio Turnover Rate
10%
Holdings [Text Block]
Table Summary
Portfolio Holdings Presented by Credit Rating S&P or Moody'sFootnote Reference*
%Footnote Reference**
  • A4.19%
  • A-0.67%
  • A+2.54%
  • AA3.91%
  • AA-1.94%
  • AA+0.95%
  • AAA0.84%
  • B1.03%
  • B-2.10%
  • B+1.53%
  • BB2.09%
  • BB-0.64%
  • BB+13.21%
  • BBB4.81%
  • BBB-9.95%
  • BBB+1.61%
  • CC0.12%
  • CCC0.34%
  • CCC-0.80%
  • CCC+0.25%
  • NR46.48%
  • Total 100.00%
FootnoteDescription
Footnote*
Investments in investment grade municipal bonds, which are bonds that are rated, at the time of purchase, within the four highest grades assigned by an independent rating agency such as Moody’s, S&P, or Fitch, or an equivalent short-term rating, as applicable, or are unrated by rating agencies but deemed by Lord Abbett to be of comparable quality. Lower rated municipal bonds are rated, at the time of purchase, or an equivalent short-term rating, as applicable, by an independent rating agency or are unrated by rating agencies but deemed by Lord Abbett to be of comparable quality.
Footnote**
Represents percent of total investments, which excludes derivatives.
Credit Ratings Selection [Text Block] Investments in investment grade municipal bonds, which are bonds that are rated, at the time of purchase, within the four highest grades assigned by an independent rating agency such as Moody’s, S&P, or Fitch, or an equivalent short-term rating, as applicable, or are unrated by rating agencies but deemed by Lord Abbett to be of comparable quality. Lower rated municipal bonds are rated, at the time of purchase, or an equivalent short-term rating, as applicable, by an independent rating agency or are unrated by rating agencies but deemed by Lord Abbett to be of comparable quality.
C000020576  
Shareholder Report [Line Items]  
Fund Name Lord Abbett California Tax Free Fund
Class Name Class A
Trading Symbol LCFIX
Annual or Semi-Annual Statement [Text Block] This semi-annual shareholder report contains important information about the Lord Abbett California Tax Free Fund for the period of October 1, 2025 to March 31, 2026.
Additional Information [Text Block] You can find additional information about the Fund at lordabbett.com/FundDocuments. You can also request this information by contacting us at 888-522-2388.
Additional Information Phone Number 888-522-2388
Additional Information Website <span style="box-sizing: border-box; color: rgb(0, 0, 0); display: inline; flex-wrap: nowrap; font-size: 13.3333px; font-weight: 400; grid-area: auto; line-height: 20px; margin: 0px; overflow: visible; text-align: left; text-align-last: auto; white-space-collapse: preserve-breaks;">lordabbett.com/FundDocuments</span>
Expenses [Text Block]

What were the Fund costs for the last period?

(based on a hypothetical $10,000 investment)

Table Summary
Class Name
Costs of a $10,000 investment
Costs paid as a percentage of a $10,000 investment
Class A
$41
0.82%Footnote Reference(a)
FootnoteDescription
Footnote(a)
Annualized.
Expenses Paid, Amount $ 41
Expense Ratio, Percent 0.82% [6]
AssetsNet $ 705,308,053
Holdings Count | Holding 290
InvestmentCompanyPortfolioTurnover 15.00%
Additional Fund Statistics [Text Block]

Key Fund Statistics

 

 (as of March 31, 2026)

Table Summary
Total Net Assets
$705,308,053
# of Portfolio Holdings
290
Portfolio Turnover Rate
15%
Holdings [Text Block]
Table Summary
Portfolio Holdings Presented by Credit Rating S&P or Moody'sFootnote Reference*
%Footnote Reference**
  • A11.31%
  • A-3.58%
  • A+6.16%
  • AA26.91%
  • AA-20.43%
  • AA+3.86%
  • AAA1.70%
  • B+0.06%
  • BB0.91%
  • BB+3.06%
  • BBB3.91%
  • BBB-4.56%
  • BBB+6.00%
  • CCC0.09%
  • CCC+0.50%
  • NR6.96%
  • Total 100.00%
FootnoteDescription
Footnote*
Investments in investment grade municipal bonds, which are bonds that are rated, at the time of purchase, within the four highest grades assigned by an independent rating agency such as Moody’s, S&P, or Fitch, or an equivalent short-term rating, as applicable, or are unrated by rating agencies but deemed by Lord Abbett to be of comparable quality. Lower rated municipal bonds are rated, at the time of purchase, or an equivalent short-term rating, as applicable, by an independent rating agency or are unrated by rating agencies but deemed by Lord Abbett to be of comparable quality.
Footnote**
Represents percent of total investments, which excludes derivatives.
Credit Ratings Selection [Text Block] Investments in investment grade municipal bonds, which are bonds that are rated, at the time of purchase, within the four highest grades assigned by an independent rating agency such as Moody’s, S&P, or Fitch, or an equivalent short-term rating, as applicable, or are unrated by rating agencies but deemed by Lord Abbett to be of comparable quality. Lower rated municipal bonds are rated, at the time of purchase, or an equivalent short-term rating, as applicable, by an independent rating agency or are unrated by rating agencies but deemed by Lord Abbett to be of comparable quality.
C000020577  
Shareholder Report [Line Items]  
Fund Name Lord Abbett California Tax Free Fund
Class Name Class C
Trading Symbol CALAX
Annual or Semi-Annual Statement [Text Block] This semi-annual shareholder report contains important information about the Lord Abbett California Tax Free Fund for the period of October 1, 2025 to March 31, 2026.
Additional Information [Text Block] You can find additional information about the Fund at lordabbett.com/FundDocuments. You can also request this information by contacting us at 888-522-2388.
Additional Information Phone Number 888-522-2388
Additional Information Website <span style="box-sizing: border-box; color: rgb(0, 0, 0); display: inline; flex-wrap: nowrap; font-size: 13.3333px; font-weight: 400; grid-area: auto; line-height: 20px; margin: 0px; overflow: visible; text-align: left; text-align-last: auto; white-space-collapse: preserve-breaks;">lordabbett.com/FundDocuments</span>
Expenses [Text Block]

What were the Fund costs for the last period?

(based on a hypothetical $10,000 investment)

Table Summary
Class Name
Costs of a $10,000 investment
Costs paid as a percentage of a $10,000 investment
Class C
$73
1.46%Footnote Reference(a)
FootnoteDescription
Footnote(a)
Annualized.
Expenses Paid, Amount $ 73
Expense Ratio, Percent 1.46% [7]
AssetsNet $ 705,308,053
Holdings Count | Holding 290
InvestmentCompanyPortfolioTurnover 15.00%
Additional Fund Statistics [Text Block]

Key Fund Statistics

 

 (as of March 31, 2026)

Table Summary
Total Net Assets
$705,308,053
# of Portfolio Holdings
290
Portfolio Turnover Rate
15%
Holdings [Text Block]
Table Summary
Portfolio Holdings Presented by Credit Rating S&P or Moody'sFootnote Reference*
%Footnote Reference**
  • A11.31%
  • A-3.58%
  • A+6.16%
  • AA26.91%
  • AA-20.43%
  • AA+3.86%
  • AAA1.70%
  • B+0.06%
  • BB0.91%
  • BB+3.06%
  • BBB3.91%
  • BBB-4.56%
  • BBB+6.00%
  • CCC0.09%
  • CCC+0.50%
  • NR6.96%
  • Total 100.00%
FootnoteDescription
Footnote*
Investments in investment grade municipal bonds, which are bonds that are rated, at the time of purchase, within the four highest grades assigned by an independent rating agency such as Moody’s, S&P, or Fitch, or an equivalent short-term rating, as applicable, or are unrated by rating agencies but deemed by Lord Abbett to be of comparable quality. Lower rated municipal bonds are rated, at the time of purchase, or an equivalent short-term rating, as applicable, by an independent rating agency or are unrated by rating agencies but deemed by Lord Abbett to be of comparable quality.
Footnote**
Represents percent of total investments, which excludes derivatives.
Credit Ratings Selection [Text Block] Investments in investment grade municipal bonds, which are bonds that are rated, at the time of purchase, within the four highest grades assigned by an independent rating agency such as Moody’s, S&P, or Fitch, or an equivalent short-term rating, as applicable, or are unrated by rating agencies but deemed by Lord Abbett to be of comparable quality. Lower rated municipal bonds are rated, at the time of purchase, or an equivalent short-term rating, as applicable, by an independent rating agency or are unrated by rating agencies but deemed by Lord Abbett to be of comparable quality.
C000054742  
Shareholder Report [Line Items]  
Fund Name Lord Abbett California Tax Free Fund
Class Name Class F
Trading Symbol LCFFX
Annual or Semi-Annual Statement [Text Block] This semi-annual shareholder report contains important information about the Lord Abbett California Tax Free Fund for the period of October 1, 2025 to March 31, 2026.
Additional Information [Text Block] You can find additional information about the Fund at lordabbett.com/FundDocuments. You can also request this information by contacting us at 888-522-2388.
Additional Information Phone Number 888-522-2388
Additional Information Website <span style="box-sizing: border-box; color: rgb(0, 0, 0); display: inline; flex-wrap: nowrap; font-size: 13.3333px; font-weight: 400; grid-area: auto; line-height: 20px; margin: 0px; overflow: visible; text-align: left; text-align-last: auto; white-space-collapse: preserve-breaks;">lordabbett.com/FundDocuments</span>
Expenses [Text Block]

What were the Fund costs for the last period?

(based on a hypothetical $10,000 investment)

Table Summary
Class Name
Costs of a $10,000 investment
Costs paid as a percentage of a $10,000 investment
Class F
$36
0.72%Footnote Reference(a)
FootnoteDescription
Footnote(a)
Annualized.
Expenses Paid, Amount $ 36
Expense Ratio, Percent 0.72% [8]
AssetsNet $ 705,308,053
Holdings Count | Holding 290
InvestmentCompanyPortfolioTurnover 15.00%
Additional Fund Statistics [Text Block]

Key Fund Statistics

 

 (as of March 31, 2026)

Table Summary
Total Net Assets
$705,308,053
# of Portfolio Holdings
290
Portfolio Turnover Rate
15%
Holdings [Text Block]
Table Summary
Portfolio Holdings Presented by Credit Rating S&P or Moody'sFootnote Reference*
%Footnote Reference**
  • A11.31%
  • A-3.58%
  • A+6.16%
  • AA26.91%
  • AA-20.43%
  • AA+3.86%
  • AAA1.70%
  • B+0.06%
  • BB0.91%
  • BB+3.06%
  • BBB3.91%
  • BBB-4.56%
  • BBB+6.00%
  • CCC0.09%
  • CCC+0.50%
  • NR6.96%
  • Total 100.00%
FootnoteDescription
Footnote*
Investments in investment grade municipal bonds, which are bonds that are rated, at the time of purchase, within the four highest grades assigned by an independent rating agency such as Moody’s, S&P, or Fitch, or an equivalent short-term rating, as applicable, or are unrated by rating agencies but deemed by Lord Abbett to be of comparable quality. Lower rated municipal bonds are rated, at the time of purchase, or an equivalent short-term rating, as applicable, by an independent rating agency or are unrated by rating agencies but deemed by Lord Abbett to be of comparable quality.
Footnote**
Represents percent of total investments, which excludes derivatives.
Credit Ratings Selection [Text Block] Investments in investment grade municipal bonds, which are bonds that are rated, at the time of purchase, within the four highest grades assigned by an independent rating agency such as Moody’s, S&P, or Fitch, or an equivalent short-term rating, as applicable, or are unrated by rating agencies but deemed by Lord Abbett to be of comparable quality. Lower rated municipal bonds are rated, at the time of purchase, or an equivalent short-term rating, as applicable, by an independent rating agency or are unrated by rating agencies but deemed by Lord Abbett to be of comparable quality.
C000188221  
Shareholder Report [Line Items]  
Fund Name Lord Abbett California Tax Free Fund
Class Name Class F3
Trading Symbol LCFOX
Annual or Semi-Annual Statement [Text Block] This semi-annual shareholder report contains important information about the Lord Abbett California Tax Free Fund for the period of October 1, 2025 to March 31, 2026.
Additional Information [Text Block] You can find additional information about the Fund at lordabbett.com/FundDocuments. You can also request this information by contacting us at 888-522-2388.
Additional Information Phone Number 888-522-2388
Additional Information Website <span style="box-sizing: border-box; color: rgb(0, 0, 0); display: inline; flex-wrap: nowrap; font-size: 13.3333px; font-weight: 400; grid-area: auto; line-height: 20px; margin: 0px; overflow: visible; text-align: left; text-align-last: auto; white-space-collapse: preserve-breaks;">lordabbett.com/FundDocuments</span>
Expenses [Text Block]

What were the Fund costs for the last period?

(based on a hypothetical $10,000 investment)

Table Summary
Class Name
Costs of a $10,000 investment
Costs paid as a percentage of a $10,000 investment
Class F3
$30
0.59%Footnote Reference(a)
FootnoteDescription
Footnote(a)
Annualized.
Expenses Paid, Amount $ 30
Expense Ratio, Percent 0.59% [9]
AssetsNet $ 705,308,053
Holdings Count | Holding 290
InvestmentCompanyPortfolioTurnover 15.00%
Additional Fund Statistics [Text Block]

Key Fund Statistics

 

 (as of March 31, 2026)

Table Summary
Total Net Assets
$705,308,053
# of Portfolio Holdings
290
Portfolio Turnover Rate
15%
Holdings [Text Block]
Table Summary
Portfolio Holdings Presented by Credit Rating S&P or Moody'sFootnote Reference*
%Footnote Reference**
  • A11.31%
  • A-3.58%
  • A+6.16%
  • AA26.91%
  • AA-20.43%
  • AA+3.86%
  • AAA1.70%
  • B+0.06%
  • BB0.91%
  • BB+3.06%
  • BBB3.91%
  • BBB-4.56%
  • BBB+6.00%
  • CCC0.09%
  • CCC+0.50%
  • NR6.96%
  • Total 100.00%
FootnoteDescription
Footnote*
Investments in investment grade municipal bonds, which are bonds that are rated, at the time of purchase, within the four highest grades assigned by an independent rating agency such as Moody’s, S&P, or Fitch, or an equivalent short-term rating, as applicable, or are unrated by rating agencies but deemed by Lord Abbett to be of comparable quality. Lower rated municipal bonds are rated, at the time of purchase, or an equivalent short-term rating, as applicable, by an independent rating agency or are unrated by rating agencies but deemed by Lord Abbett to be of comparable quality.
Footnote**
Represents percent of total investments, which excludes derivatives.
Credit Ratings Selection [Text Block] Investments in investment grade municipal bonds, which are bonds that are rated, at the time of purchase, within the four highest grades assigned by an independent rating agency such as Moody’s, S&P, or Fitch, or an equivalent short-term rating, as applicable, or are unrated by rating agencies but deemed by Lord Abbett to be of comparable quality. Lower rated municipal bonds are rated, at the time of purchase, or an equivalent short-term rating, as applicable, by an independent rating agency or are unrated by rating agencies but deemed by Lord Abbett to be of comparable quality.
C000096845  
Shareholder Report [Line Items]  
Fund Name Lord Abbett California Tax Free Fund
Class Name Class I
Trading Symbol CAILX
Annual or Semi-Annual Statement [Text Block] This semi-annual shareholder report contains important information about the Lord Abbett California Tax Free Fund for the period of October 1, 2025 to March 31, 2026.
Additional Information [Text Block] You can find additional information about the Fund at lordabbett.com/FundDocuments. You can also request this information by contacting us at 888-522-2388.
Additional Information Phone Number 888-522-2388
Additional Information Website <span style="box-sizing: border-box; color: rgb(0, 0, 0); display: inline; flex-wrap: nowrap; font-size: 13.3333px; font-weight: 400; grid-area: auto; line-height: 20px; margin: 0px; overflow: visible; text-align: left; text-align-last: auto; white-space-collapse: preserve-breaks;">lordabbett.com/FundDocuments</span>
Expenses [Text Block]

What were the Fund costs for the last period?

(based on a hypothetical $10,000 investment)

Table Summary
Class Name
Costs of a $10,000 investment
Costs paid as a percentage of a $10,000 investment
Class I
$31
0.62%Footnote Reference(a)
FootnoteDescription
Footnote(a)
Annualized.
Expenses Paid, Amount $ 31
Expense Ratio, Percent 0.62% [10]
AssetsNet $ 705,308,053
Holdings Count | Holding 290
InvestmentCompanyPortfolioTurnover 15.00%
Additional Fund Statistics [Text Block]

Key Fund Statistics

 

 (as of March 31, 2026)

Table Summary
Total Net Assets
$705,308,053
# of Portfolio Holdings
290
Portfolio Turnover Rate
15%
Holdings [Text Block]
Table Summary
Portfolio Holdings Presented by Credit Rating S&P or Moody'sFootnote Reference*
%Footnote Reference**
  • A11.31%
  • A-3.58%
  • A+6.16%
  • AA26.91%
  • AA-20.43%
  • AA+3.86%
  • AAA1.70%
  • B+0.06%
  • BB0.91%
  • BB+3.06%
  • BBB3.91%
  • BBB-4.56%
  • BBB+6.00%
  • CCC0.09%
  • CCC+0.50%
  • NR6.96%
  • Total 100.00%
FootnoteDescription
Footnote*
Investments in investment grade municipal bonds, which are bonds that are rated, at the time of purchase, within the four highest grades assigned by an independent rating agency such as Moody’s, S&P, or Fitch, or an equivalent short-term rating, as applicable, or are unrated by rating agencies but deemed by Lord Abbett to be of comparable quality. Lower rated municipal bonds are rated, at the time of purchase, or an equivalent short-term rating, as applicable, by an independent rating agency or are unrated by rating agencies but deemed by Lord Abbett to be of comparable quality.
Footnote**
Represents percent of total investments, which excludes derivatives.
Credit Ratings Selection [Text Block] Investments in investment grade municipal bonds, which are bonds that are rated, at the time of purchase, within the four highest grades assigned by an independent rating agency such as Moody’s, S&P, or Fitch, or an equivalent short-term rating, as applicable, or are unrated by rating agencies but deemed by Lord Abbett to be of comparable quality. Lower rated municipal bonds are rated, at the time of purchase, or an equivalent short-term rating, as applicable, by an independent rating agency or are unrated by rating agencies but deemed by Lord Abbett to be of comparable quality.
C000096630  
Shareholder Report [Line Items]  
Fund Name Lord Abbett Intermediate Tax Free Fund
Class Name Class A
Trading Symbol LISAX
Annual or Semi-Annual Statement [Text Block] This semi-annual shareholder report contains important information about the Lord Abbett Intermediate Tax Free Fund for the period of October 1, 2025 to March 31, 2026.
Additional Information [Text Block] You can find additional information about the Fund at lordabbett.com/FundDocuments. You can also request this information by contacting us at 888-522-2388.
Additional Information Phone Number 888-522-2388
Additional Information Website <span style="box-sizing: border-box; color: rgb(0, 0, 0); display: inline; flex-wrap: nowrap; font-size: 13.3333px; font-weight: 400; grid-area: auto; line-height: 20px; margin: 0px; overflow: visible; text-align: left; text-align-last: auto; white-space-collapse: preserve-breaks;">lordabbett.com/FundDocuments</span>
Expenses [Text Block]

What were the Fund costs for the last period?

(based on a hypothetical $10,000 investment)

Table Summary
Class Name
Costs of a $10,000 investment
Costs paid as a percentage of a $10,000 investment
Class A
$36
0.71%Footnote Reference(a)
FootnoteDescription
Footnote(a)
Annualized.
Expenses Paid, Amount $ 36
Expense Ratio, Percent 0.71% [11]
AssetsNet $ 5,463,859,080
Holdings Count | Holding 924
InvestmentCompanyPortfolioTurnover 18.00%
Additional Fund Statistics [Text Block]

Key Fund Statistics

 

 (as of March 31, 2026)

Table Summary
Total Net Assets
$5,463,859,080
# of Portfolio Holdings
924
Portfolio Turnover Rate
18%
Holdings [Text Block]
Table Summary
Portfolio Holdings Presented by Credit Rating S&P or Moody'sFootnote Reference*
%Footnote Reference**
  • A12.83%
  • A-4.25%
  • A+16.62%
  • AA11.69%
  • AA-8.42%
  • AA+8.67%
  • AAA6.92%
  • B0.27%
  • B-0.31%
  • B+0.52%
  • BB1.77%
  • BB-0.28%
  • BB+3.24%
  • BBB5.82%
  • BBB-4.93%
  • BBB+5.09%
  • CCC+0.18%
  • NR8.19%
  • Total 100.00%
FootnoteDescription
Footnote*
Investments in investment grade municipal bonds, which are bonds that are rated, at the time of purchase, within the four highest grades assigned by an independent rating agency such as Moody’s, S&P, or Fitch, or an equivalent short-term rating, as applicable, or are unrated by rating agencies but deemed by Lord Abbett to be of comparable quality. Lower rated municipal bonds are rated, at the time of purchase, or an equivalent short-term rating, as applicable, by an independent rating agency or are unrated by rating agencies but deemed by Lord Abbett to be of comparable quality.
Footnote**
Represents percent of total investments, which excludes derivatives.
Credit Ratings Selection [Text Block] Investments in investment grade municipal bonds, which are bonds that are rated, at the time of purchase, within the four highest grades assigned by an independent rating agency such as Moody’s, S&P, or Fitch, or an equivalent short-term rating, as applicable, or are unrated by rating agencies but deemed by Lord Abbett to be of comparable quality. Lower rated municipal bonds are rated, at the time of purchase, or an equivalent short-term rating, as applicable, by an independent rating agency or are unrated by rating agencies but deemed by Lord Abbett to be of comparable quality.
C000096632  
Shareholder Report [Line Items]  
Fund Name Lord Abbett Intermediate Tax Free Fund
Class Name Class C
Trading Symbol LISCX
Annual or Semi-Annual Statement [Text Block] This semi-annual shareholder report contains important information about the Lord Abbett Intermediate Tax Free Fund for the period of October 1, 2025 to March 31, 2026.
Additional Information [Text Block] You can find additional information about the Fund at lordabbett.com/FundDocuments. You can also request this information by contacting us at 888-522-2388.
Additional Information Phone Number 888-522-2388
Additional Information Website <span style="box-sizing: border-box; color: rgb(0, 0, 0); display: inline; flex-wrap: nowrap; font-size: 13.3333px; font-weight: 400; grid-area: auto; line-height: 20px; margin: 0px; overflow: visible; text-align: left; text-align-last: auto; white-space-collapse: preserve-breaks;">lordabbett.com/FundDocuments</span>
Expenses [Text Block]

What were the Fund costs for the last period?

(based on a hypothetical $10,000 investment)

Table Summary
Class Name
Costs of a $10,000 investment
Costs paid as a percentage of a $10,000 investment
Class C
$67
1.33%Footnote Reference(a)
FootnoteDescription
Footnote(a)
Annualized.
Expenses Paid, Amount $ 67
Expense Ratio, Percent 1.33% [12]
AssetsNet $ 5,463,859,080
Holdings Count | Holding 924
InvestmentCompanyPortfolioTurnover 18.00%
Additional Fund Statistics [Text Block]

Key Fund Statistics

 

 (as of March 31, 2026)

Table Summary
Total Net Assets
$5,463,859,080
# of Portfolio Holdings
924
Portfolio Turnover Rate
18%
Holdings [Text Block]
Table Summary
Portfolio Holdings Presented by Credit Rating S&P or Moody'sFootnote Reference*
%Footnote Reference**
  • A12.83%
  • A-4.25%
  • A+16.62%
  • AA11.69%
  • AA-8.42%
  • AA+8.67%
  • AAA6.92%
  • B0.27%
  • B-0.31%
  • B+0.52%
  • BB1.77%
  • BB-0.28%
  • BB+3.24%
  • BBB5.82%
  • BBB-4.93%
  • BBB+5.09%
  • CCC+0.18%
  • NR8.19%
  • Total 100.00%
FootnoteDescription
Footnote*
Investments in investment grade municipal bonds, which are bonds that are rated, at the time of purchase, within the four highest grades assigned by an independent rating agency such as Moody’s, S&P, or Fitch, or an equivalent short-term rating, as applicable, or are unrated by rating agencies but deemed by Lord Abbett to be of comparable quality. Lower rated municipal bonds are rated, at the time of purchase, or an equivalent short-term rating, as applicable, by an independent rating agency or are unrated by rating agencies but deemed by Lord Abbett to be of comparable quality.
Footnote**
Represents percent of total investments, which excludes derivatives.
Credit Ratings Selection [Text Block] Investments in investment grade municipal bonds, which are bonds that are rated, at the time of purchase, within the four highest grades assigned by an independent rating agency such as Moody’s, S&P, or Fitch, or an equivalent short-term rating, as applicable, or are unrated by rating agencies but deemed by Lord Abbett to be of comparable quality. Lower rated municipal bonds are rated, at the time of purchase, or an equivalent short-term rating, as applicable, by an independent rating agency or are unrated by rating agencies but deemed by Lord Abbett to be of comparable quality.
C000096627  
Shareholder Report [Line Items]  
Fund Name Lord Abbett Intermediate Tax Free Fund
Class Name Class F
Trading Symbol LISFX
Annual or Semi-Annual Statement [Text Block] This semi-annual shareholder report contains important information about the Lord Abbett Intermediate Tax Free Fund for the period of October 1, 2025 to March 31, 2026.
Additional Information [Text Block] You can find additional information about the Fund at lordabbett.com/FundDocuments. You can also request this information by contacting us at 888-522-2388.
Additional Information Phone Number 888-522-2388
Additional Information Website <span style="box-sizing: border-box; color: rgb(0, 0, 0); display: inline; flex-wrap: nowrap; font-size: 13.3333px; font-weight: 400; grid-area: auto; line-height: 20px; margin: 0px; overflow: visible; text-align: left; text-align-last: auto; white-space-collapse: preserve-breaks;">lordabbett.com/FundDocuments</span>
Expenses [Text Block]

What were the Fund costs for the last period?

(based on a hypothetical $10,000 investment)

Table Summary
Class Name
Costs of a $10,000 investment
Costs paid as a percentage of a $10,000 investment
Class F
$31
0.61%Footnote Reference(a)
FootnoteDescription
Footnote(a)
Annualized.
Expenses Paid, Amount $ 31
Expense Ratio, Percent 0.61% [13]
AssetsNet $ 5,463,859,080
Holdings Count | Holding 924
InvestmentCompanyPortfolioTurnover 18.00%
Additional Fund Statistics [Text Block]

Key Fund Statistics

 

 (as of March 31, 2026)

Table Summary
Total Net Assets
$5,463,859,080
# of Portfolio Holdings
924
Portfolio Turnover Rate
18%
Holdings [Text Block]
Table Summary
Portfolio Holdings Presented by Credit Rating S&P or Moody'sFootnote Reference*
%Footnote Reference**
  • A12.83%
  • A-4.25%
  • A+16.62%
  • AA11.69%
  • AA-8.42%
  • AA+8.67%
  • AAA6.92%
  • B0.27%
  • B-0.31%
  • B+0.52%
  • BB1.77%
  • BB-0.28%
  • BB+3.24%
  • BBB5.82%
  • BBB-4.93%
  • BBB+5.09%
  • CCC+0.18%
  • NR8.19%
  • Total 100.00%
FootnoteDescription
Footnote*
Investments in investment grade municipal bonds, which are bonds that are rated, at the time of purchase, within the four highest grades assigned by an independent rating agency such as Moody’s, S&P, or Fitch, or an equivalent short-term rating, as applicable, or are unrated by rating agencies but deemed by Lord Abbett to be of comparable quality. Lower rated municipal bonds are rated, at the time of purchase, or an equivalent short-term rating, as applicable, by an independent rating agency or are unrated by rating agencies but deemed by Lord Abbett to be of comparable quality.
Footnote**
Represents percent of total investments, which excludes derivatives.
Credit Ratings Selection [Text Block] Investments in investment grade municipal bonds, which are bonds that are rated, at the time of purchase, within the four highest grades assigned by an independent rating agency such as Moody’s, S&P, or Fitch, or an equivalent short-term rating, as applicable, or are unrated by rating agencies but deemed by Lord Abbett to be of comparable quality. Lower rated municipal bonds are rated, at the time of purchase, or an equivalent short-term rating, as applicable, by an independent rating agency or are unrated by rating agencies but deemed by Lord Abbett to be of comparable quality.
C000188227  
Shareholder Report [Line Items]  
Fund Name Lord Abbett Intermediate Tax Free Fund
Class Name Class F3
Trading Symbol LOISX
Annual or Semi-Annual Statement [Text Block] This semi-annual shareholder report contains important information about the Lord Abbett Intermediate Tax Free Fund for the period of October 1, 2025 to March 31, 2026.
Additional Information [Text Block] You can find additional information about the Fund at lordabbett.com/FundDocuments. You can also request this information by contacting us at 888-522-2388.
Additional Information Phone Number 888-522-2388
Additional Information Website <span style="box-sizing: border-box; color: rgb(0, 0, 0); display: inline; flex-wrap: nowrap; font-size: 13.3333px; font-weight: 400; grid-area: auto; line-height: 20px; margin: 0px; overflow: visible; text-align: left; text-align-last: auto; white-space-collapse: preserve-breaks;">lordabbett.com/FundDocuments</span>
Expenses [Text Block]

What were the Fund costs for the last period?

(based on a hypothetical $10,000 investment)

Table Summary
Class Name
Costs of a $10,000 investment
Costs paid as a percentage of a $10,000 investment
Class F3
$23
0.45%Footnote Reference(a)
FootnoteDescription
Footnote(a)
Annualized.
Expenses Paid, Amount $ 23
Expense Ratio, Percent 0.45% [14]
AssetsNet $ 5,463,859,080
Holdings Count | Holding 924
InvestmentCompanyPortfolioTurnover 18.00%
Additional Fund Statistics [Text Block]

Key Fund Statistics

 

 (as of March 31, 2026)

Table Summary
Total Net Assets
$5,463,859,080
# of Portfolio Holdings
924
Portfolio Turnover Rate
18%
Holdings [Text Block]
Table Summary
Portfolio Holdings Presented by Credit Rating S&P or Moody'sFootnote Reference*
%Footnote Reference**
  • A12.83%
  • A-4.25%
  • A+16.62%
  • AA11.69%
  • AA-8.42%
  • AA+8.67%
  • AAA6.92%
  • B0.27%
  • B-0.31%
  • B+0.52%
  • BB1.77%
  • BB-0.28%
  • BB+3.24%
  • BBB5.82%
  • BBB-4.93%
  • BBB+5.09%
  • CCC+0.18%
  • NR8.19%
  • Total 100.00%
FootnoteDescription
Footnote*
Investments in investment grade municipal bonds, which are bonds that are rated, at the time of purchase, within the four highest grades assigned by an independent rating agency such as Moody’s, S&P, or Fitch, or an equivalent short-term rating, as applicable, or are unrated by rating agencies but deemed by Lord Abbett to be of comparable quality. Lower rated municipal bonds are rated, at the time of purchase, or an equivalent short-term rating, as applicable, by an independent rating agency or are unrated by rating agencies but deemed by Lord Abbett to be of comparable quality.
Footnote**
Represents percent of total investments, which excludes derivatives.
Credit Ratings Selection [Text Block] Investments in investment grade municipal bonds, which are bonds that are rated, at the time of purchase, within the four highest grades assigned by an independent rating agency such as Moody’s, S&P, or Fitch, or an equivalent short-term rating, as applicable, or are unrated by rating agencies but deemed by Lord Abbett to be of comparable quality. Lower rated municipal bonds are rated, at the time of purchase, or an equivalent short-term rating, as applicable, by an independent rating agency or are unrated by rating agencies but deemed by Lord Abbett to be of comparable quality.
C000096628  
Shareholder Report [Line Items]  
Fund Name Lord Abbett Intermediate Tax Free Fund
Class Name Class I
Trading Symbol LAIIX
Annual or Semi-Annual Statement [Text Block] This semi-annual shareholder report contains important information about the Lord Abbett Intermediate Tax Free Fund for the period of October 1, 2025 to March 31, 2026.
Additional Information [Text Block] You can find additional information about the Fund at lordabbett.com/FundDocuments. You can also request this information by contacting us at 888-522-2388.
Additional Information Phone Number 888-522-2388
Additional Information Website <span style="box-sizing: border-box; color: rgb(0, 0, 0); display: inline; flex-wrap: nowrap; font-size: 13.3333px; font-weight: 400; grid-area: auto; line-height: 20px; margin: 0px; overflow: visible; text-align: left; text-align-last: auto; white-space-collapse: preserve-breaks;">lordabbett.com/FundDocuments</span>
Expenses [Text Block]

What were the Fund costs for the last period?

(based on a hypothetical $10,000 investment)

Table Summary
Class Name
Costs of a $10,000 investment
Costs paid as a percentage of a $10,000 investment
Class I
$26
0.51%Footnote Reference(a)
FootnoteDescription
Footnote(a)
Annualized.
Expenses Paid, Amount $ 26
Expense Ratio, Percent 0.51% [15]
AssetsNet $ 5,463,859,080
Holdings Count | Holding 924
InvestmentCompanyPortfolioTurnover 18.00%
Additional Fund Statistics [Text Block]

Key Fund Statistics

 

 (as of March 31, 2026)

Table Summary
Total Net Assets
$5,463,859,080
# of Portfolio Holdings
924
Portfolio Turnover Rate
18%
Holdings [Text Block]
Table Summary
Portfolio Holdings Presented by Credit Rating S&P or Moody'sFootnote Reference*
%Footnote Reference**
  • A12.83%
  • A-4.25%
  • A+16.62%
  • AA11.69%
  • AA-8.42%
  • AA+8.67%
  • AAA6.92%
  • B0.27%
  • B-0.31%
  • B+0.52%
  • BB1.77%
  • BB-0.28%
  • BB+3.24%
  • BBB5.82%
  • BBB-4.93%
  • BBB+5.09%
  • CCC+0.18%
  • NR8.19%
  • Total 100.00%
FootnoteDescription
Footnote*
Investments in investment grade municipal bonds, which are bonds that are rated, at the time of purchase, within the four highest grades assigned by an independent rating agency such as Moody’s, S&P, or Fitch, or an equivalent short-term rating, as applicable, or are unrated by rating agencies but deemed by Lord Abbett to be of comparable quality. Lower rated municipal bonds are rated, at the time of purchase, or an equivalent short-term rating, as applicable, by an independent rating agency or are unrated by rating agencies but deemed by Lord Abbett to be of comparable quality.
Footnote**
Represents percent of total investments, which excludes derivatives.
Credit Ratings Selection [Text Block] Investments in investment grade municipal bonds, which are bonds that are rated, at the time of purchase, within the four highest grades assigned by an independent rating agency such as Moody’s, S&P, or Fitch, or an equivalent short-term rating, as applicable, or are unrated by rating agencies but deemed by Lord Abbett to be of comparable quality. Lower rated municipal bonds are rated, at the time of purchase, or an equivalent short-term rating, as applicable, by an independent rating agency or are unrated by rating agencies but deemed by Lord Abbett to be of comparable quality.
C000020589  
Shareholder Report [Line Items]  
Fund Name Lord Abbett National Tax Free Fund
Class Name Class A
Trading Symbol LANSX
Annual or Semi-Annual Statement [Text Block] This semi-annual shareholder report contains important information about the Lord Abbett National Tax Free Fund for the period of October 1, 2025 to March 31, 2026.
Additional Information [Text Block] You can find additional information about the Fund at lordabbett.com/FundDocuments. You can also request this information by contacting us at 888-522-2388.
Additional Information Phone Number 888-522-2388
Additional Information Website <span style="box-sizing: border-box; color: rgb(0, 0, 0); display: inline; flex-wrap: nowrap; font-size: 13.3333px; font-weight: 400; grid-area: auto; line-height: 20px; margin: 0px; overflow: visible; text-align: left; text-align-last: auto; white-space-collapse: preserve-breaks;">lordabbett.com/FundDocuments</span>
Expenses [Text Block]

What were the Fund costs for the last period?

(based on a hypothetical $10,000 investment)

Table Summary
Class Name
Costs of a $10,000 investment
Costs paid as a percentage of a $10,000 investment
Class A
$41
0.81%Footnote Reference(a)
FootnoteDescription
Footnote(a)
Annualized.
Expenses Paid, Amount $ 41
Expense Ratio, Percent 0.81% [16]
AssetsNet $ 4,814,052,700
Holdings Count | Holding 709
InvestmentCompanyPortfolioTurnover 17.00%
Additional Fund Statistics [Text Block]

Key Fund Statistics

 

 (as of March 31, 2026)

Table Summary
Total Net Assets
$4,814,052,700
# of Portfolio Holdings
709
Portfolio Turnover Rate
17%
Holdings [Text Block]
Table Summary
Portfolio Holdings Presented by Credit Rating S&P or Moody'sFootnote Reference*
%Footnote Reference**
  • A12.57%
  • A-3.04%
  • A+12.27%
  • AA14.98%
  • AA-6.84%
  • AA+8.40%
  • AAA4.22%
  • B0.07%
  • B-0.62%
  • B+0.27%
  • BB1.14%
  • BB-0.14%
  • BB+3.92%
  • BBB6.41%
  • BBB-10.56%
  • BBB+6.16%
  • CCC+0.51%
  • NR7.88%
  • Total 100.00%
FootnoteDescription
Footnote*
Investments in investment grade municipal bonds, which are bonds that are rated, at the time of purchase, within the four highest grades assigned by an independent rating agency such as Moody’s, S&P, or Fitch, or an equivalent short-term rating, as applicable, or are unrated by rating agencies but deemed by Lord Abbett to be of comparable quality. Lower rated municipal bonds are rated, at the time of purchase, or an equivalent short-term rating, as applicable, by an independent rating agency or are unrated by rating agencies but deemed by Lord Abbett to be of comparable quality.
Footnote**
Represents percent of total investments, which excludes derivatives.
Credit Ratings Selection [Text Block] Investments in investment grade municipal bonds, which are bonds that are rated, at the time of purchase, within the four highest grades assigned by an independent rating agency such as Moody’s, S&P, or Fitch, or an equivalent short-term rating, as applicable, or are unrated by rating agencies but deemed by Lord Abbett to be of comparable quality. Lower rated municipal bonds are rated, at the time of purchase, or an equivalent short-term rating, as applicable, by an independent rating agency or are unrated by rating agencies but deemed by Lord Abbett to be of comparable quality.
C000020591  
Shareholder Report [Line Items]  
Fund Name Lord Abbett National Tax Free Fund
Class Name Class C
Trading Symbol LTNSX
Annual or Semi-Annual Statement [Text Block] This semi-annual shareholder report contains important information about the Lord Abbett National Tax Free Fund for the period of October 1, 2025 to March 31, 2026.
Additional Information [Text Block] You can find additional information about the Fund at lordabbett.com/FundDocuments. You can also request this information by contacting us at 888-522-2388.
Additional Information Phone Number 888-522-2388
Additional Information Website <span style="box-sizing: border-box; color: rgb(0, 0, 0); display: inline; flex-wrap: nowrap; font-size: 13.3333px; font-weight: 400; grid-area: auto; line-height: 20px; margin: 0px; overflow: visible; text-align: left; text-align-last: auto; white-space-collapse: preserve-breaks;">lordabbett.com/FundDocuments</span>
Expenses [Text Block]

What were the Fund costs for the last period?

(based on a hypothetical $10,000 investment)

Table Summary
Class Name
Costs of a $10,000 investment
Costs paid as a percentage of a $10,000 investment
Class C
$72
1.44%Footnote Reference(a)
FootnoteDescription
Footnote(a)
Annualized.
Expenses Paid, Amount $ 72
Expense Ratio, Percent 1.44% [17]
AssetsNet $ 4,814,052,700
Holdings Count | Holding 709
InvestmentCompanyPortfolioTurnover 17.00%
Additional Fund Statistics [Text Block]

Key Fund Statistics

 

 (as of March 31, 2026)

Table Summary
Total Net Assets
$4,814,052,700
# of Portfolio Holdings
709
Portfolio Turnover Rate
17%
Holdings [Text Block]
Table Summary
Portfolio Holdings Presented by Credit Rating S&P or Moody'sFootnote Reference*
%Footnote Reference**
  • A12.57%
  • A-3.04%
  • A+12.27%
  • AA14.98%
  • AA-6.84%
  • AA+8.40%
  • AAA4.22%
  • B0.07%
  • B-0.62%
  • B+0.27%
  • BB1.14%
  • BB-0.14%
  • BB+3.92%
  • BBB6.41%
  • BBB-10.56%
  • BBB+6.16%
  • CCC+0.51%
  • NR7.88%
  • Total 100.00%
FootnoteDescription
Footnote*
Investments in investment grade municipal bonds, which are bonds that are rated, at the time of purchase, within the four highest grades assigned by an independent rating agency such as Moody’s, S&P, or Fitch, or an equivalent short-term rating, as applicable, or are unrated by rating agencies but deemed by Lord Abbett to be of comparable quality. Lower rated municipal bonds are rated, at the time of purchase, or an equivalent short-term rating, as applicable, by an independent rating agency or are unrated by rating agencies but deemed by Lord Abbett to be of comparable quality.
Footnote**
Represents percent of total investments, which excludes derivatives.
Credit Ratings Selection [Text Block] Investments in investment grade municipal bonds, which are bonds that are rated, at the time of purchase, within the four highest grades assigned by an independent rating agency such as Moody’s, S&P, or Fitch, or an equivalent short-term rating, as applicable, or are unrated by rating agencies but deemed by Lord Abbett to be of comparable quality. Lower rated municipal bonds are rated, at the time of purchase, or an equivalent short-term rating, as applicable, by an independent rating agency or are unrated by rating agencies but deemed by Lord Abbett to be of comparable quality.
C000054746  
Shareholder Report [Line Items]  
Fund Name Lord Abbett National Tax Free Fund
Class Name Class F
Trading Symbol LANFX
Annual or Semi-Annual Statement [Text Block] This semi-annual shareholder report contains important information about the Lord Abbett National Tax Free Fund for the period of October 1, 2025 to March 31, 2026.
Additional Information [Text Block] You can find additional information about the Fund at lordabbett.com/FundDocuments. You can also request this information by contacting us at 888-522-2388.
Additional Information Phone Number 888-522-2388
Additional Information Website <span style="box-sizing: border-box; color: rgb(0, 0, 0); display: inline; flex-wrap: nowrap; font-size: 13.3333px; font-weight: 400; grid-area: auto; line-height: 20px; margin: 0px; overflow: visible; text-align: left; text-align-last: auto; white-space-collapse: preserve-breaks;">lordabbett.com/FundDocuments</span>
Expenses [Text Block]

What were the Fund costs for the last period?

(based on a hypothetical $10,000 investment)

Table Summary
Class Name
Costs of a $10,000 investment
Costs paid as a percentage of a $10,000 investment
Class F
$36
0.71%Footnote Reference(a)
FootnoteDescription
Footnote(a)
Annualized.
Expenses Paid, Amount $ 36
Expense Ratio, Percent 0.71% [18]
AssetsNet $ 4,814,052,700
Holdings Count | Holding 709
InvestmentCompanyPortfolioTurnover 17.00%
Additional Fund Statistics [Text Block]

Key Fund Statistics

 

 (as of March 31, 2026)

Table Summary
Total Net Assets
$4,814,052,700
# of Portfolio Holdings
709
Portfolio Turnover Rate
17%
Holdings [Text Block]
Table Summary
Portfolio Holdings Presented by Credit Rating S&P or Moody'sFootnote Reference*
%Footnote Reference**
  • A12.57%
  • A-3.04%
  • A+12.27%
  • AA14.98%
  • AA-6.84%
  • AA+8.40%
  • AAA4.22%
  • B0.07%
  • B-0.62%
  • B+0.27%
  • BB1.14%
  • BB-0.14%
  • BB+3.92%
  • BBB6.41%
  • BBB-10.56%
  • BBB+6.16%
  • CCC+0.51%
  • NR7.88%
  • Total 100.00%
FootnoteDescription
Footnote*
Investments in investment grade municipal bonds, which are bonds that are rated, at the time of purchase, within the four highest grades assigned by an independent rating agency such as Moody’s, S&P, or Fitch, or an equivalent short-term rating, as applicable, or are unrated by rating agencies but deemed by Lord Abbett to be of comparable quality. Lower rated municipal bonds are rated, at the time of purchase, or an equivalent short-term rating, as applicable, by an independent rating agency or are unrated by rating agencies but deemed by Lord Abbett to be of comparable quality.
Footnote**
Represents percent of total investments, which excludes derivatives.
Credit Ratings Selection [Text Block] Investments in investment grade municipal bonds, which are bonds that are rated, at the time of purchase, within the four highest grades assigned by an independent rating agency such as Moody’s, S&P, or Fitch, or an equivalent short-term rating, as applicable, or are unrated by rating agencies but deemed by Lord Abbett to be of comparable quality. Lower rated municipal bonds are rated, at the time of purchase, or an equivalent short-term rating, as applicable, by an independent rating agency or are unrated by rating agencies but deemed by Lord Abbett to be of comparable quality.
C000188222  
Shareholder Report [Line Items]  
Fund Name Lord Abbett National Tax Free Fund
Class Name Class F3
Trading Symbol LONSX
Annual or Semi-Annual Statement [Text Block] This semi-annual shareholder report contains important information about the Lord Abbett National Tax Free Fund for the period of October 1, 2025 to March 31, 2026.
Additional Information [Text Block] You can find additional information about the Fund at lordabbett.com/FundDocuments. You can also request this information by contacting us at 888-522-2388.
Additional Information Phone Number 888-522-2388
Additional Information Website <span style="box-sizing: border-box; color: rgb(0, 0, 0); display: inline; flex-wrap: nowrap; font-size: 13.3333px; font-weight: 400; grid-area: auto; line-height: 20px; margin: 0px; overflow: visible; text-align: left; text-align-last: auto; white-space-collapse: preserve-breaks;">lordabbett.com/FundDocuments</span>
Expenses [Text Block]

What were the Fund costs for the last period?

(based on a hypothetical $10,000 investment)

Table Summary
Class Name
Costs of a $10,000 investment
Costs paid as a percentage of a $10,000 investment
Class F3
$28
0.56%Footnote Reference(a)
FootnoteDescription
Footnote(a)
Annualized.
Expenses Paid, Amount $ 28
Expense Ratio, Percent 0.56% [19]
AssetsNet $ 4,814,052,700
Holdings Count | Holding 709
InvestmentCompanyPortfolioTurnover 17.00%
Additional Fund Statistics [Text Block]

Key Fund Statistics

 

 (as of March 31, 2026)

Table Summary
Total Net Assets
$4,814,052,700
# of Portfolio Holdings
709
Portfolio Turnover Rate
17%
Holdings [Text Block]
Table Summary
Portfolio Holdings Presented by Credit Rating S&P or Moody'sFootnote Reference*
%Footnote Reference**
  • A12.57%
  • A-3.04%
  • A+12.27%
  • AA14.98%
  • AA-6.84%
  • AA+8.40%
  • AAA4.22%
  • B0.07%
  • B-0.62%
  • B+0.27%
  • BB1.14%
  • BB-0.14%
  • BB+3.92%
  • BBB6.41%
  • BBB-10.56%
  • BBB+6.16%
  • CCC+0.51%
  • NR7.88%
  • Total 100.00%
FootnoteDescription
Footnote*
Investments in investment grade municipal bonds, which are bonds that are rated, at the time of purchase, within the four highest grades assigned by an independent rating agency such as Moody’s, S&P, or Fitch, or an equivalent short-term rating, as applicable, or are unrated by rating agencies but deemed by Lord Abbett to be of comparable quality. Lower rated municipal bonds are rated, at the time of purchase, or an equivalent short-term rating, as applicable, by an independent rating agency or are unrated by rating agencies but deemed by Lord Abbett to be of comparable quality.
Footnote**
Represents percent of total investments, which excludes derivatives.
Credit Ratings Selection [Text Block] Investments in investment grade municipal bonds, which are bonds that are rated, at the time of purchase, within the four highest grades assigned by an independent rating agency such as Moody’s, S&P, or Fitch, or an equivalent short-term rating, as applicable, or are unrated by rating agencies but deemed by Lord Abbett to be of comparable quality. Lower rated municipal bonds are rated, at the time of purchase, or an equivalent short-term rating, as applicable, by an independent rating agency or are unrated by rating agencies but deemed by Lord Abbett to be of comparable quality.
C000050290  
Shareholder Report [Line Items]  
Fund Name Lord Abbett National Tax Free Fund
Class Name Class I
Trading Symbol LTNIX
Annual or Semi-Annual Statement [Text Block] This semi-annual shareholder report contains important information about the Lord Abbett National Tax Free Fund for the period of October 1, 2025 to March 31, 2026.
Additional Information [Text Block] You can find additional information about the Fund at lordabbett.com/FundDocuments. You can also request this information by contacting us at 888-522-2388.
Additional Information Phone Number 888-522-2388
Additional Information Website <span style="box-sizing: border-box; color: rgb(0, 0, 0); display: inline; flex-wrap: nowrap; font-size: 13.3333px; font-weight: 400; grid-area: auto; line-height: 20px; margin: 0px; overflow: visible; text-align: left; text-align-last: auto; white-space-collapse: preserve-breaks;">lordabbett.com/FundDocuments</span>
Expenses [Text Block]

What were the Fund costs for the last period?

(based on a hypothetical $10,000 investment)

Table Summary
Class Name
Costs of a $10,000 investment
Costs paid as a percentage of a $10,000 investment
Class I
$31
0.61%Footnote Reference(a)
FootnoteDescription
Footnote(a)
Annualized.
Expenses Paid, Amount $ 31
Expense Ratio, Percent 0.61% [20]
AssetsNet $ 4,814,052,700
Holdings Count | Holding 709
InvestmentCompanyPortfolioTurnover 17.00%
Additional Fund Statistics [Text Block]

Key Fund Statistics

 

 (as of March 31, 2026)

Table Summary
Total Net Assets
$4,814,052,700
# of Portfolio Holdings
709
Portfolio Turnover Rate
17%
Holdings [Text Block]
Table Summary
Portfolio Holdings Presented by Credit Rating S&P or Moody'sFootnote Reference*
%Footnote Reference**
  • A12.57%
  • A-3.04%
  • A+12.27%
  • AA14.98%
  • AA-6.84%
  • AA+8.40%
  • AAA4.22%
  • B0.07%
  • B-0.62%
  • B+0.27%
  • BB1.14%
  • BB-0.14%
  • BB+3.92%
  • BBB6.41%
  • BBB-10.56%
  • BBB+6.16%
  • CCC+0.51%
  • NR7.88%
  • Total 100.00%
FootnoteDescription
Footnote*
Investments in investment grade municipal bonds, which are bonds that are rated, at the time of purchase, within the four highest grades assigned by an independent rating agency such as Moody’s, S&P, or Fitch, or an equivalent short-term rating, as applicable, or are unrated by rating agencies but deemed by Lord Abbett to be of comparable quality. Lower rated municipal bonds are rated, at the time of purchase, or an equivalent short-term rating, as applicable, by an independent rating agency or are unrated by rating agencies but deemed by Lord Abbett to be of comparable quality.
Footnote**
Represents percent of total investments, which excludes derivatives.
Credit Ratings Selection [Text Block] Investments in investment grade municipal bonds, which are bonds that are rated, at the time of purchase, within the four highest grades assigned by an independent rating agency such as Moody’s, S&P, or Fitch, or an equivalent short-term rating, as applicable, or are unrated by rating agencies but deemed by Lord Abbett to be of comparable quality. Lower rated municipal bonds are rated, at the time of purchase, or an equivalent short-term rating, as applicable, by an independent rating agency or are unrated by rating agencies but deemed by Lord Abbett to be of comparable quality.
C000020593  
Shareholder Report [Line Items]  
Fund Name Lord Abbett New Jersey Tax Free Fund
Class Name Class A
Trading Symbol LANJX
Annual or Semi-Annual Statement [Text Block] This semi-annual shareholder report contains important information about the Lord Abbett New Jersey Tax Free Fund for the period of October 1, 2025 to March 31, 2026.
Additional Information [Text Block] You can find additional information about the Fund at lordabbett.com/FundDocuments. You can also request this information by contacting us at 888-522-2388.
Additional Information Phone Number 888-522-2388
Additional Information Website <span style="box-sizing: border-box; color: rgb(0, 0, 0); display: inline; flex-wrap: nowrap; font-size: 13.3333px; font-weight: 400; grid-area: auto; line-height: 20px; margin: 0px; overflow: visible; text-align: left; text-align-last: auto; white-space-collapse: preserve-breaks;">lordabbett.com/FundDocuments</span>
Expenses [Text Block]

What were the Fund costs for the last period?

(based on a hypothetical $10,000 investment)

Table Summary
Class Name
Costs of a $10,000 investment
Costs paid as a percentage of a $10,000 investment
Class A
$42
0.84%Footnote Reference(a)
FootnoteDescription
Footnote(a)
Annualized.
Expenses Paid, Amount $ 42
Expense Ratio, Percent 0.84% [21]
AssetsNet $ 172,859,708
Holdings Count | Holding 199
InvestmentCompanyPortfolioTurnover 3.00%
Additional Fund Statistics [Text Block]

Key Fund Statistics

 

 (as of March 31, 2026)

Table Summary
Total Net Assets
$172,859,708
# of Portfolio Holdings
199
Portfolio Turnover Rate
3%
Holdings [Text Block]
Table Summary
Portfolio Holdings Presented by Credit Rating S&P or Moody'sFootnote Reference*
%Footnote Reference**
  • A7.30%
  • A-3.57%
  • A+24.97%
  • AA13.89%
  • AA-26.95%
  • AA+0.85%
  • AAA5.62%
  • B+0.14%
  • BB+2.40%
  • BBB2.50%
  • BBB-3.40%
  • BBB+3.64%
  • NR4.77%
  • Total 100.00%
FootnoteDescription
Footnote*
Investments in investment grade municipal bonds, which are bonds that are rated, at the time of purchase, within the four highest grades assigned by an independent rating agency such as Moody’s, S&P, or Fitch, or an equivalent short-term rating, as applicable, or are unrated by rating agencies but deemed by Lord Abbett to be of comparable quality. Lower rated municipal bonds are rated, at the time of purchase, or an equivalent short-term rating, as applicable, by an independent rating agency or are unrated by rating agencies but deemed by Lord Abbett to be of comparable quality.
Footnote**
Represents percent of total investments, which excludes derivatives.
Credit Ratings Selection [Text Block] Investments in investment grade municipal bonds, which are bonds that are rated, at the time of purchase, within the four highest grades assigned by an independent rating agency such as Moody’s, S&P, or Fitch, or an equivalent short-term rating, as applicable, or are unrated by rating agencies but deemed by Lord Abbett to be of comparable quality. Lower rated municipal bonds are rated, at the time of purchase, or an equivalent short-term rating, as applicable, by an independent rating agency or are unrated by rating agencies but deemed by Lord Abbett to be of comparable quality.
C000054747  
Shareholder Report [Line Items]  
Fund Name Lord Abbett New Jersey Tax Free Fund
Class Name Class F
Trading Symbol LNJFX
Annual or Semi-Annual Statement [Text Block] This semi-annual shareholder report contains important information about the Lord Abbett New Jersey Tax Free Fund for the period of October 1, 2025 to March 31, 2026.
Additional Information [Text Block] You can find additional information about the Fund at lordabbett.com/FundDocuments. You can also request this information by contacting us at 888-522-2388.
Additional Information Phone Number 888-522-2388
Additional Information Website <span style="box-sizing: border-box; color: rgb(0, 0, 0); display: inline; flex-wrap: nowrap; font-size: 13.3333px; font-weight: 400; grid-area: auto; line-height: 20px; margin: 0px; overflow: visible; text-align: left; text-align-last: auto; white-space-collapse: preserve-breaks;">lordabbett.com/FundDocuments</span>
Expenses [Text Block]

What were the Fund costs for the last period?

(based on a hypothetical $10,000 investment)

Table Summary
Class Name
Costs of a $10,000 investment
Costs paid as a percentage of a $10,000 investment
Class F
$37
0.74%Footnote Reference(a)
FootnoteDescription
Footnote(a)
Annualized.
Expenses Paid, Amount $ 37
Expense Ratio, Percent 0.74% [22]
AssetsNet $ 172,859,708
Holdings Count | Holding 199
InvestmentCompanyPortfolioTurnover 3.00%
Additional Fund Statistics [Text Block]

Key Fund Statistics

 

 (as of March 31, 2026)

Table Summary
Total Net Assets
$172,859,708
# of Portfolio Holdings
199
Portfolio Turnover Rate
3%
Holdings [Text Block]
Table Summary
Portfolio Holdings Presented by Credit Rating S&P or Moody'sFootnote Reference*
%Footnote Reference**
  • A7.30%
  • A-3.57%
  • A+24.97%
  • AA13.89%
  • AA-26.95%
  • AA+0.85%
  • AAA5.62%
  • B+0.14%
  • BB+2.40%
  • BBB2.50%
  • BBB-3.40%
  • BBB+3.64%
  • NR4.77%
  • Total 100.00%
FootnoteDescription
Footnote*
Investments in investment grade municipal bonds, which are bonds that are rated, at the time of purchase, within the four highest grades assigned by an independent rating agency such as Moody’s, S&P, or Fitch, or an equivalent short-term rating, as applicable, or are unrated by rating agencies but deemed by Lord Abbett to be of comparable quality. Lower rated municipal bonds are rated, at the time of purchase, or an equivalent short-term rating, as applicable, by an independent rating agency or are unrated by rating agencies but deemed by Lord Abbett to be of comparable quality.
Footnote**
Represents percent of total investments, which excludes derivatives.
Credit Ratings Selection [Text Block] Investments in investment grade municipal bonds, which are bonds that are rated, at the time of purchase, within the four highest grades assigned by an independent rating agency such as Moody’s, S&P, or Fitch, or an equivalent short-term rating, as applicable, or are unrated by rating agencies but deemed by Lord Abbett to be of comparable quality. Lower rated municipal bonds are rated, at the time of purchase, or an equivalent short-term rating, as applicable, by an independent rating agency or are unrated by rating agencies but deemed by Lord Abbett to be of comparable quality.
C000188223  
Shareholder Report [Line Items]  
Fund Name Lord Abbett New Jersey Tax Free Fund
Class Name Class F3
Trading Symbol LONJX
Annual or Semi-Annual Statement [Text Block] This semi-annual shareholder report contains important information about the Lord Abbett New Jersey Tax Free Fund for the period of October 1, 2025 to March 31, 2026.
Additional Information [Text Block] You can find additional information about the Fund at lordabbett.com/FundDocuments. You can also request this information by contacting us at 888-522-2388.
Additional Information Phone Number 888-522-2388
Additional Information Website <span style="box-sizing: border-box; color: rgb(0, 0, 0); display: inline; flex-wrap: nowrap; font-size: 13.3333px; font-weight: 400; grid-area: auto; line-height: 20px; margin: 0px; overflow: visible; text-align: left; text-align-last: auto; white-space-collapse: preserve-breaks;">lordabbett.com/FundDocuments</span>
Expenses [Text Block]

What were the Fund costs for the last period?

(based on a hypothetical $10,000 investment)

Table Summary
Class Name
Costs of a $10,000 investment
Costs paid as a percentage of a $10,000 investment
Class F3
$31
0.61%Footnote Reference(a)
FootnoteDescription
Footnote(a)
Annualized.
Expenses Paid, Amount $ 31
Expense Ratio, Percent 0.61% [23]
AssetsNet $ 172,859,708
Holdings Count | Holding 199
InvestmentCompanyPortfolioTurnover 3.00%
Additional Fund Statistics [Text Block]

Key Fund Statistics

 

 (as of March 31, 2026)

Table Summary
Total Net Assets
$172,859,708
# of Portfolio Holdings
199
Portfolio Turnover Rate
3%
Holdings [Text Block]
Table Summary
Portfolio Holdings Presented by Credit Rating S&P or Moody'sFootnote Reference*
%Footnote Reference**
  • A7.30%
  • A-3.57%
  • A+24.97%
  • AA13.89%
  • AA-26.95%
  • AA+0.85%
  • AAA5.62%
  • B+0.14%
  • BB+2.40%
  • BBB2.50%
  • BBB-3.40%
  • BBB+3.64%
  • NR4.77%
  • Total 100.00%
FootnoteDescription
Footnote*
Investments in investment grade municipal bonds, which are bonds that are rated, at the time of purchase, within the four highest grades assigned by an independent rating agency such as Moody’s, S&P, or Fitch, or an equivalent short-term rating, as applicable, or are unrated by rating agencies but deemed by Lord Abbett to be of comparable quality. Lower rated municipal bonds are rated, at the time of purchase, or an equivalent short-term rating, as applicable, by an independent rating agency or are unrated by rating agencies but deemed by Lord Abbett to be of comparable quality.
Footnote**
Represents percent of total investments, which excludes derivatives.
Credit Ratings Selection [Text Block] Investments in investment grade municipal bonds, which are bonds that are rated, at the time of purchase, within the four highest grades assigned by an independent rating agency such as Moody’s, S&P, or Fitch, or an equivalent short-term rating, as applicable, or are unrated by rating agencies but deemed by Lord Abbett to be of comparable quality. Lower rated municipal bonds are rated, at the time of purchase, or an equivalent short-term rating, as applicable, by an independent rating agency or are unrated by rating agencies but deemed by Lord Abbett to be of comparable quality.
C000096846  
Shareholder Report [Line Items]  
Fund Name Lord Abbett New Jersey Tax Free Fund
Class Name Class I
Trading Symbol LINJX
Annual or Semi-Annual Statement [Text Block] This semi-annual shareholder report contains important information about the Lord Abbett New Jersey Tax Free Fund for the period of October 1, 2025 to March 31, 2026.
Additional Information [Text Block] You can find additional information about the Fund at lordabbett.com/FundDocuments. You can also request this information by contacting us at 888-522-2388.
Additional Information Phone Number 888-522-2388
Additional Information Website <span style="box-sizing: border-box; color: rgb(0, 0, 0); display: inline; flex-wrap: nowrap; font-size: 13.3333px; font-weight: 400; grid-area: auto; line-height: 20px; margin: 0px; overflow: visible; text-align: left; text-align-last: auto; white-space-collapse: preserve-breaks;">lordabbett.com/FundDocuments</span>
Expenses [Text Block]

What were the Fund costs for the last period?

(based on a hypothetical $10,000 investment)

Table Summary
Class Name
Costs of a $10,000 investment
Costs paid as a percentage of a $10,000 investment
Class I
$32
0.64%Footnote Reference(a)
FootnoteDescription
Footnote(a)
Annualized.
Expenses Paid, Amount $ 32
Expense Ratio, Percent 0.64% [24]
AssetsNet $ 172,859,708
Holdings Count | Holding 199
InvestmentCompanyPortfolioTurnover 3.00%
Additional Fund Statistics [Text Block]

Key Fund Statistics

 

 (as of March 31, 2026)

Table Summary
Total Net Assets
$172,859,708
# of Portfolio Holdings
199
Portfolio Turnover Rate
3%
Holdings [Text Block]
Table Summary
Portfolio Holdings Presented by Credit Rating S&P or Moody'sFootnote Reference*
%Footnote Reference**
  • A7.30%
  • A-3.57%
  • A+24.97%
  • AA13.89%
  • AA-26.95%
  • AA+0.85%
  • AAA5.62%
  • B+0.14%
  • BB+2.40%
  • BBB2.50%
  • BBB-3.40%
  • BBB+3.64%
  • NR4.77%
  • Total 100.00%
FootnoteDescription
Footnote*
Investments in investment grade municipal bonds, which are bonds that are rated, at the time of purchase, within the four highest grades assigned by an independent rating agency such as Moody’s, S&P, or Fitch, or an equivalent short-term rating, as applicable, or are unrated by rating agencies but deemed by Lord Abbett to be of comparable quality. Lower rated municipal bonds are rated, at the time of purchase, or an equivalent short-term rating, as applicable, by an independent rating agency or are unrated by rating agencies but deemed by Lord Abbett to be of comparable quality.
Footnote**
Represents percent of total investments, which excludes derivatives.
Credit Ratings Selection [Text Block] Investments in investment grade municipal bonds, which are bonds that are rated, at the time of purchase, within the four highest grades assigned by an independent rating agency such as Moody’s, S&P, or Fitch, or an equivalent short-term rating, as applicable, or are unrated by rating agencies but deemed by Lord Abbett to be of comparable quality. Lower rated municipal bonds are rated, at the time of purchase, or an equivalent short-term rating, as applicable, by an independent rating agency or are unrated by rating agencies but deemed by Lord Abbett to be of comparable quality.
C000096633  
Shareholder Report [Line Items]  
Fund Name Lord Abbett Short Duration Tax Free Fund
Class Name Class A
Trading Symbol LSDAX
Annual or Semi-Annual Statement [Text Block] This semi-annual shareholder report contains important information about the Lord Abbett Short Duration Tax Free Fund for the period of October 1, 2025 to March 31, 2026.
Additional Information [Text Block] You can find additional information about the Fund at lordabbett.com/FundDocuments. You can also request this information by contacting us at 888-522-2388.
Additional Information Phone Number 888-522-2388
Additional Information Website <span style="box-sizing: border-box; color: rgb(0, 0, 0); display: inline; flex-wrap: nowrap; font-size: 13.3333px; font-weight: 400; grid-area: auto; line-height: 20px; margin: 0px; overflow: visible; text-align: left; text-align-last: auto; white-space-collapse: preserve-breaks;">lordabbett.com/FundDocuments</span>
Expenses [Text Block]

What were the Fund costs for the last period?

(based on a hypothetical $10,000 investment)

Table Summary
Class Name
Costs of a $10,000 investment
Costs paid as a percentage of a $10,000 investment
Class A
$33
0.65%Footnote Reference(a)
FootnoteDescription
Footnote(a)
Annualized.
Expenses Paid, Amount $ 33
Expense Ratio, Percent 0.65% [25]
AssetsNet $ 1,718,068,772
Holdings Count | Holding 270
InvestmentCompanyPortfolioTurnover 35.00%
Additional Fund Statistics [Text Block]

Key Fund Statistics

 

 (as of March 31, 2026)

Table Summary
Total Net Assets
$1,718,068,772
# of Portfolio Holdings
270
Portfolio Turnover Rate
35%
Holdings [Text Block]
Table Summary
Portfolio Holdings Presented by Credit Rating S&P or Moody'sFootnote Reference*
%Footnote Reference**
  • A17.58%
  • A-8.45%
  • A+15.77%
  • AA9.79%
  • AA-8.16%
  • AA+12.44%
  • AAA5.83%
  • B0.06%
  • BB1.01%
  • BB+0.36%
  • BBB2.18%
  • BBB-3.48%
  • BBB+3.39%
  • CCC+0.57%
  • NR10.93%
  • Total 100.00%
FootnoteDescription
Footnote*
Investments in investment grade municipal bonds, which are bonds that are rated, at the time of purchase, within the four highest grades assigned by an independent rating agency such as Moody’s, S&P, or Fitch, or an equivalent short-term rating, as applicable, or are unrated by rating agencies but deemed by Lord Abbett to be of comparable quality. Lower rated municipal bonds are rated, at the time of purchase, or an equivalent short-term rating, as applicable, by an independent rating agency or are unrated by rating agencies but deemed by Lord Abbett to be of comparable quality.
Footnote**
Represents percent of total investments, which excludes derivatives.
Credit Ratings Selection [Text Block] Investments in investment grade municipal bonds, which are bonds that are rated, at the time of purchase, within the four highest grades assigned by an independent rating agency such as Moody’s, S&P, or Fitch, or an equivalent short-term rating, as applicable, or are unrated by rating agencies but deemed by Lord Abbett to be of comparable quality. Lower rated municipal bonds are rated, at the time of purchase, or an equivalent short-term rating, as applicable, by an independent rating agency or are unrated by rating agencies but deemed by Lord Abbett to be of comparable quality.
C000096635  
Shareholder Report [Line Items]  
Fund Name Lord Abbett Short Duration Tax Free Fund
Class Name Class C
Trading Symbol LSDCX
Annual or Semi-Annual Statement [Text Block] This semi-annual shareholder report contains important information about the Lord Abbett Short Duration Tax Free Fund for the period of October 1, 2025 to March 31, 2026.
Additional Information [Text Block] You can find additional information about the Fund at lordabbett.com/FundDocuments. You can also request this information by contacting us at 888-522-2388.
Additional Information Phone Number 888-522-2388
Additional Information Website <span style="box-sizing: border-box; color: rgb(0, 0, 0); display: inline; flex-wrap: nowrap; font-size: 13.3333px; font-weight: 400; grid-area: auto; line-height: 20px; margin: 0px; overflow: visible; text-align: left; text-align-last: auto; white-space-collapse: preserve-breaks;">lordabbett.com/FundDocuments</span>
Expenses [Text Block]

What were the Fund costs for the last period?

(based on a hypothetical $10,000 investment)

Table Summary
Class Name
Costs of a $10,000 investment
Costs paid as a percentage of a $10,000 investment
Class C
$64
1.29%Footnote Reference(a)
FootnoteDescription
Footnote(a)
Annualized.
Expenses Paid, Amount $ 64
Expense Ratio, Percent 1.29% [26]
AssetsNet $ 1,718,068,772
Holdings Count | Holding 270
InvestmentCompanyPortfolioTurnover 35.00%
Additional Fund Statistics [Text Block]

Key Fund Statistics

 

 (as of March 31, 2026)

Table Summary
Total Net Assets
$1,718,068,772
# of Portfolio Holdings
270
Portfolio Turnover Rate
35%
Holdings [Text Block]
Table Summary
Portfolio Holdings Presented by Credit Rating S&P or Moody'sFootnote Reference*
%Footnote Reference**
  • A17.58%
  • A-8.45%
  • A+15.77%
  • AA9.79%
  • AA-8.16%
  • AA+12.44%
  • AAA5.83%
  • B0.06%
  • BB1.01%
  • BB+0.36%
  • BBB2.18%
  • BBB-3.48%
  • BBB+3.39%
  • CCC+0.57%
  • NR10.93%
  • Total 100.00%
FootnoteDescription
Footnote*
Investments in investment grade municipal bonds, which are bonds that are rated, at the time of purchase, within the four highest grades assigned by an independent rating agency such as Moody’s, S&P, or Fitch, or an equivalent short-term rating, as applicable, or are unrated by rating agencies but deemed by Lord Abbett to be of comparable quality. Lower rated municipal bonds are rated, at the time of purchase, or an equivalent short-term rating, as applicable, by an independent rating agency or are unrated by rating agencies but deemed by Lord Abbett to be of comparable quality.
Footnote**
Represents percent of total investments, which excludes derivatives.
Credit Ratings Selection [Text Block] Investments in investment grade municipal bonds, which are bonds that are rated, at the time of purchase, within the four highest grades assigned by an independent rating agency such as Moody’s, S&P, or Fitch, or an equivalent short-term rating, as applicable, or are unrated by rating agencies but deemed by Lord Abbett to be of comparable quality. Lower rated municipal bonds are rated, at the time of purchase, or an equivalent short-term rating, as applicable, by an independent rating agency or are unrated by rating agencies but deemed by Lord Abbett to be of comparable quality.
C000096636  
Shareholder Report [Line Items]  
Fund Name Lord Abbett Short Duration Tax Free Fund
Class Name Class F
Trading Symbol LSDFX
Annual or Semi-Annual Statement [Text Block] This semi-annual shareholder report contains important information about the Lord Abbett Short Duration Tax Free Fund for the period of October 1, 2025 to March 31, 2026.
Additional Information [Text Block] You can find additional information about the Fund at lordabbett.com/FundDocuments. You can also request this information by contacting us at 888-522-2388.
Additional Information Phone Number 888-522-2388
Additional Information Website <span style="box-sizing: border-box; color: rgb(0, 0, 0); display: inline; flex-wrap: nowrap; font-size: 13.3333px; font-weight: 400; grid-area: auto; line-height: 20px; margin: 0px; overflow: visible; text-align: left; text-align-last: auto; white-space-collapse: preserve-breaks;">lordabbett.com/FundDocuments</span>
Expenses [Text Block]

What were the Fund costs for the last period?

(based on a hypothetical $10,000 investment)

Table Summary
Class Name
Costs of a $10,000 investment
Costs paid as a percentage of a $10,000 investment
Class F
$28
0.55%Footnote Reference(a)
FootnoteDescription
Footnote(a)
Annualized.
Expenses Paid, Amount $ 28
Expense Ratio, Percent 0.55% [27]
AssetsNet $ 1,718,068,772
Holdings Count | Holding 270
InvestmentCompanyPortfolioTurnover 35.00%
Additional Fund Statistics [Text Block]

Key Fund Statistics

 

 (as of March 31, 2026)

Table Summary
Total Net Assets
$1,718,068,772
# of Portfolio Holdings
270
Portfolio Turnover Rate
35%
Holdings [Text Block]
Table Summary
Portfolio Holdings Presented by Credit Rating S&P or Moody'sFootnote Reference*
%Footnote Reference**
  • A17.58%
  • A-8.45%
  • A+15.77%
  • AA9.79%
  • AA-8.16%
  • AA+12.44%
  • AAA5.83%
  • B0.06%
  • BB1.01%
  • BB+0.36%
  • BBB2.18%
  • BBB-3.48%
  • BBB+3.39%
  • CCC+0.57%
  • NR10.93%
  • Total 100.00%
FootnoteDescription
Footnote*
Investments in investment grade municipal bonds, which are bonds that are rated, at the time of purchase, within the four highest grades assigned by an independent rating agency such as Moody’s, S&P, or Fitch, or an equivalent short-term rating, as applicable, or are unrated by rating agencies but deemed by Lord Abbett to be of comparable quality. Lower rated municipal bonds are rated, at the time of purchase, or an equivalent short-term rating, as applicable, by an independent rating agency or are unrated by rating agencies but deemed by Lord Abbett to be of comparable quality.
Footnote**
Represents percent of total investments, which excludes derivatives.
Credit Ratings Selection [Text Block] Investments in investment grade municipal bonds, which are bonds that are rated, at the time of purchase, within the four highest grades assigned by an independent rating agency such as Moody’s, S&P, or Fitch, or an equivalent short-term rating, as applicable, or are unrated by rating agencies but deemed by Lord Abbett to be of comparable quality. Lower rated municipal bonds are rated, at the time of purchase, or an equivalent short-term rating, as applicable, by an independent rating agency or are unrated by rating agencies but deemed by Lord Abbett to be of comparable quality.
C000188228  
Shareholder Report [Line Items]  
Fund Name Lord Abbett Short Duration Tax Free Fund
Class Name Class F3
Trading Symbol LSDOX
Annual or Semi-Annual Statement [Text Block] This semi-annual shareholder report contains important information about the Lord Abbett Short Duration Tax Free Fund for the period of October 1, 2025 to March 31, 2026.
Additional Information [Text Block] You can find additional information about the Fund at lordabbett.com/FundDocuments. You can also request this information by contacting us at 888-522-2388.
Additional Information Phone Number 888-522-2388
Additional Information Website <span style="box-sizing: border-box; color: rgb(0, 0, 0); display: inline; flex-wrap: nowrap; font-size: 13.3333px; font-weight: 400; grid-area: auto; line-height: 20px; margin: 0px; overflow: visible; text-align: left; text-align-last: auto; white-space-collapse: preserve-breaks;">lordabbett.com/FundDocuments</span>
Expenses [Text Block]

What were the Fund costs for the last period?

(based on a hypothetical $10,000 investment)

Table Summary
Class Name
Costs of a $10,000 investment
Costs paid as a percentage of a $10,000 investment
Class F3
$21
0.41%Footnote Reference(a)
FootnoteDescription
Footnote(a)
Annualized.
Expenses Paid, Amount $ 21
Expense Ratio, Percent 0.41% [28]
AssetsNet $ 1,718,068,772
Holdings Count | Holding 270
InvestmentCompanyPortfolioTurnover 35.00%
Additional Fund Statistics [Text Block]

Key Fund Statistics

 

 (as of March 31, 2026)

Table Summary
Total Net Assets
$1,718,068,772
# of Portfolio Holdings
270
Portfolio Turnover Rate
35%
Holdings [Text Block]
Table Summary
Portfolio Holdings Presented by Credit Rating S&P or Moody'sFootnote Reference*
%Footnote Reference**
  • A17.58%
  • A-8.45%
  • A+15.77%
  • AA9.79%
  • AA-8.16%
  • AA+12.44%
  • AAA5.83%
  • B0.06%
  • BB1.01%
  • BB+0.36%
  • BBB2.18%
  • BBB-3.48%
  • BBB+3.39%
  • CCC+0.57%
  • NR10.93%
  • Total 100.00%
FootnoteDescription
Footnote*
Investments in investment grade municipal bonds, which are bonds that are rated, at the time of purchase, within the four highest grades assigned by an independent rating agency such as Moody’s, S&P, or Fitch, or an equivalent short-term rating, as applicable, or are unrated by rating agencies but deemed by Lord Abbett to be of comparable quality. Lower rated municipal bonds are rated, at the time of purchase, or an equivalent short-term rating, as applicable, by an independent rating agency or are unrated by rating agencies but deemed by Lord Abbett to be of comparable quality.
Footnote**
Represents percent of total investments, which excludes derivatives.
Credit Ratings Selection [Text Block] Investments in investment grade municipal bonds, which are bonds that are rated, at the time of purchase, within the four highest grades assigned by an independent rating agency such as Moody’s, S&P, or Fitch, or an equivalent short-term rating, as applicable, or are unrated by rating agencies but deemed by Lord Abbett to be of comparable quality. Lower rated municipal bonds are rated, at the time of purchase, or an equivalent short-term rating, as applicable, by an independent rating agency or are unrated by rating agencies but deemed by Lord Abbett to be of comparable quality.
C000096637  
Shareholder Report [Line Items]  
Fund Name Lord Abbett Short Duration Tax Free Fund
Class Name Class I
Trading Symbol LISDX
Annual or Semi-Annual Statement [Text Block] This semi-annual shareholder report contains important information about the Lord Abbett Short Duration Tax Free Fund for the period of October 1, 2025 to March 31, 2026.
Additional Information [Text Block] You can find additional information about the Fund at lordabbett.com/FundDocuments. You can also request this information by contacting us at 888-522-2388.
Additional Information Phone Number 888-522-2388
Additional Information Website <span style="box-sizing: border-box; color: rgb(0, 0, 0); display: inline; flex-wrap: nowrap; font-size: 13.3333px; font-weight: 400; grid-area: auto; line-height: 20px; margin: 0px; overflow: visible; text-align: left; text-align-last: auto; white-space-collapse: preserve-breaks;">lordabbett.com/FundDocuments</span>
Expenses [Text Block]

What were the Fund costs for the last period?

(based on a hypothetical $10,000 investment)

Table Summary
Class Name
Costs of a $10,000 investment
Costs paid as a percentage of a $10,000 investment
Class I
$23
0.45%Footnote Reference(a)
FootnoteDescription
Footnote(a)
Annualized.
Expenses Paid, Amount $ 23
Expense Ratio, Percent 0.45% [29]
AssetsNet $ 1,718,068,772
Holdings Count | Holding 270
InvestmentCompanyPortfolioTurnover 35.00%
Additional Fund Statistics [Text Block]

Key Fund Statistics

 

 (as of March 31, 2026)

Table Summary
Total Net Assets
$1,718,068,772
# of Portfolio Holdings
270
Portfolio Turnover Rate
35%
Holdings [Text Block]
Table Summary
Portfolio Holdings Presented by Credit Rating S&P or Moody'sFootnote Reference*
%Footnote Reference**
  • A17.58%
  • A-8.45%
  • A+15.77%
  • AA9.79%
  • AA-8.16%
  • AA+12.44%
  • AAA5.83%
  • B0.06%
  • BB1.01%
  • BB+0.36%
  • BBB2.18%
  • BBB-3.48%
  • BBB+3.39%
  • CCC+0.57%
  • NR10.93%
  • Total 100.00%
FootnoteDescription
Footnote*
Investments in investment grade municipal bonds, which are bonds that are rated, at the time of purchase, within the four highest grades assigned by an independent rating agency such as Moody’s, S&P, or Fitch, or an equivalent short-term rating, as applicable, or are unrated by rating agencies but deemed by Lord Abbett to be of comparable quality. Lower rated municipal bonds are rated, at the time of purchase, or an equivalent short-term rating, as applicable, by an independent rating agency or are unrated by rating agencies but deemed by Lord Abbett to be of comparable quality.
Footnote**
Represents percent of total investments, which excludes derivatives.
Credit Ratings Selection [Text Block] Investments in investment grade municipal bonds, which are bonds that are rated, at the time of purchase, within the four highest grades assigned by an independent rating agency such as Moody’s, S&P, or Fitch, or an equivalent short-term rating, as applicable, or are unrated by rating agencies but deemed by Lord Abbett to be of comparable quality. Lower rated municipal bonds are rated, at the time of purchase, or an equivalent short-term rating, as applicable, by an independent rating agency or are unrated by rating agencies but deemed by Lord Abbett to be of comparable quality.
C000020595  
Shareholder Report [Line Items]  
Fund Name Lord Abbett New York Tax Free Fund
Class Name Class A
Trading Symbol LANYX
Annual or Semi-Annual Statement [Text Block] This semi-annual shareholder report contains important information about the Lord Abbett New York Tax Free Fund for the period of October 1, 2025 to March 31, 2026.
Additional Information [Text Block] You can find additional information about the Fund at lordabbett.com/FundDocuments. You can also request this information by contacting us at 888-522-2388.
Additional Information Phone Number 888-522-2388
Additional Information Website <span style="box-sizing: border-box; color: rgb(0, 0, 0); display: inline; flex-wrap: nowrap; font-size: 13.3333px; font-weight: 400; grid-area: auto; line-height: 20px; margin: 0px; overflow: visible; text-align: left; text-align-last: auto; white-space-collapse: preserve-breaks;">lordabbett.com/FundDocuments</span>
Expenses [Text Block]

What were the Fund costs for the last period?

(based on a hypothetical $10,000 investment)

Table Summary
Class Name
Costs of a $10,000 investment
Costs paid as a percentage of a $10,000 investment
Class A
$43
0.85%Footnote Reference(a)
FootnoteDescription
Footnote(a)
Annualized.
Expenses Paid, Amount $ 43
Expense Ratio, Percent 0.85% [30]
AssetsNet $ 590,836,462
Holdings Count | Holding 285
InvestmentCompanyPortfolioTurnover 15.00%
Additional Fund Statistics [Text Block]

Key Fund Statistics

 

 (as of March 31, 2026)

Table Summary
Total Net Assets
$590,836,462
# of Portfolio Holdings
285
Portfolio Turnover Rate
15%
Holdings [Text Block]
Table Summary
Portfolio Holdings Presented by Credit Rating S&P or Moody'sFootnote Reference*
%Footnote Reference**
  • A9.18%
  • A-2.40%
  • A+4.83%
  • AA12.51%
  • AA-3.90%
  • AA+14.55%
  • AAA9.76%
  • B0.89%
  • B-0.51%
  • B+1.10%
  • BB1.54%
  • BB-0.65%
  • BB+0.54%
  • BBB9.69%
  • BBB-13.04%
  • BBB+7.21%
  • CC0.25%
  • NR7.45%
  • Total 100.00%
FootnoteDescription
Footnote*
Investments in investment grade municipal bonds, which are bonds that are rated, at the time of purchase, within the four highest grades assigned by an independent rating agency such as Moody’s, S&P, or Fitch, or an equivalent short-term rating, as applicable, or are unrated by rating agencies but deemed by Lord Abbett to be of comparable quality. Lower rated municipal bonds are rated, at the time of purchase, or an equivalent short-term rating, as applicable, by an independent rating agency or are unrated by rating agencies but deemed by Lord Abbett to be of comparable quality.
Footnote**
Represents percent of total investments, which excludes derivatives.
Credit Ratings Selection [Text Block] Investments in investment grade municipal bonds, which are bonds that are rated, at the time of purchase, within the four highest grades assigned by an independent rating agency such as Moody’s, S&P, or Fitch, or an equivalent short-term rating, as applicable, or are unrated by rating agencies but deemed by Lord Abbett to be of comparable quality. Lower rated municipal bonds are rated, at the time of purchase, or an equivalent short-term rating, as applicable, by an independent rating agency or are unrated by rating agencies but deemed by Lord Abbett to be of comparable quality.
C000020596  
Shareholder Report [Line Items]  
Fund Name Lord Abbett New York Tax Free Fund
Class Name Class C
Trading Symbol NYLAX
Annual or Semi-Annual Statement [Text Block] This semi-annual shareholder report contains important information about the Lord Abbett New York Tax Free Fund for the period of October 1, 2025 to March 31, 2026.
Additional Information [Text Block] You can find additional information about the Fund at lordabbett.com/FundDocuments. You can also request this information by contacting us at 888-522-2388.
Additional Information Phone Number 888-522-2388
Additional Information Website <span style="box-sizing: border-box; color: rgb(0, 0, 0); display: inline; flex-wrap: nowrap; font-size: 13.3333px; font-weight: 400; grid-area: auto; line-height: 20px; margin: 0px; overflow: visible; text-align: left; text-align-last: auto; white-space-collapse: preserve-breaks;">lordabbett.com/FundDocuments</span>
Expenses [Text Block]

What were the Fund costs for the last period?

(based on a hypothetical $10,000 investment)

Table Summary
Class Name
Costs of a $10,000 investment
Costs paid as a percentage of a $10,000 investment
Class C
$75
1.50%Footnote Reference(a)
FootnoteDescription
Footnote(a)
Annualized.
Expenses Paid, Amount $ 75
Expense Ratio, Percent 1.50% [31]
AssetsNet $ 590,836,462
Holdings Count | Holding 285
InvestmentCompanyPortfolioTurnover 15.00%
Additional Fund Statistics [Text Block]

Key Fund Statistics

 

 (as of March 31, 2026)

Table Summary
Total Net Assets
$590,836,462
# of Portfolio Holdings
285
Portfolio Turnover Rate
15%
Holdings [Text Block]
Table Summary
Portfolio Holdings Presented by Credit Rating S&P or Moody'sFootnote Reference*
%Footnote Reference**
  • A9.18%
  • A-2.40%
  • A+4.83%
  • AA12.51%
  • AA-3.90%
  • AA+14.55%
  • AAA9.76%
  • B0.89%
  • B-0.51%
  • B+1.10%
  • BB1.54%
  • BB-0.65%
  • BB+0.54%
  • BBB9.69%
  • BBB-13.04%
  • BBB+7.21%
  • CC0.25%
  • NR7.45%
  • Total 100.00%
FootnoteDescription
Footnote*
Investments in investment grade municipal bonds, which are bonds that are rated, at the time of purchase, within the four highest grades assigned by an independent rating agency such as Moody’s, S&P, or Fitch, or an equivalent short-term rating, as applicable, or are unrated by rating agencies but deemed by Lord Abbett to be of comparable quality. Lower rated municipal bonds are rated, at the time of purchase, or an equivalent short-term rating, as applicable, by an independent rating agency or are unrated by rating agencies but deemed by Lord Abbett to be of comparable quality.
Footnote**
Represents percent of total investments, which excludes derivatives.
Credit Ratings Selection [Text Block] Investments in investment grade municipal bonds, which are bonds that are rated, at the time of purchase, within the four highest grades assigned by an independent rating agency such as Moody’s, S&P, or Fitch, or an equivalent short-term rating, as applicable, or are unrated by rating agencies but deemed by Lord Abbett to be of comparable quality. Lower rated municipal bonds are rated, at the time of purchase, or an equivalent short-term rating, as applicable, by an independent rating agency or are unrated by rating agencies but deemed by Lord Abbett to be of comparable quality.
C000054748  
Shareholder Report [Line Items]  
Fund Name Lord Abbett New York Tax Free Fund
Class Name Class F
Trading Symbol LNYFX
Annual or Semi-Annual Statement [Text Block] This semi-annual shareholder report contains important information about the Lord Abbett New York Tax Free Fund for the period of October 1, 2025 to March 31, 2026.
Additional Information [Text Block] You can find additional information about the Fund at lordabbett.com/FundDocuments. You can also request this information by contacting us at 888-522-2388.
Additional Information Phone Number 888-522-2388
Additional Information Website <span style="box-sizing: border-box; color: rgb(0, 0, 0); display: inline; flex-wrap: nowrap; font-size: 13.3333px; font-weight: 400; grid-area: auto; line-height: 20px; margin: 0px; overflow: visible; text-align: left; text-align-last: auto; white-space-collapse: preserve-breaks;">lordabbett.com/FundDocuments</span>
Expenses [Text Block]

What were the Fund costs for the last period?

(based on a hypothetical $10,000 investment)

Table Summary
Class Name
Costs of a $10,000 investment
Costs paid as a percentage of a $10,000 investment
Class F
$38
0.75%Footnote Reference(a)
FootnoteDescription
Footnote(a)
Annualized.
Expenses Paid, Amount $ 38
Expense Ratio, Percent 0.75% [32]
AssetsNet $ 590,836,462
Holdings Count | Holding 285
InvestmentCompanyPortfolioTurnover 15.00%
Additional Fund Statistics [Text Block]

Key Fund Statistics

 

 (as of March 31, 2026)

Table Summary
Total Net Assets
$590,836,462
# of Portfolio Holdings
285
Portfolio Turnover Rate
15%
Holdings [Text Block]
Table Summary
Portfolio Holdings Presented by Credit Rating S&P or Moody'sFootnote Reference*
%Footnote Reference**
  • A9.18%
  • A-2.40%
  • A+4.83%
  • AA12.51%
  • AA-3.90%
  • AA+14.55%
  • AAA9.76%
  • B0.89%
  • B-0.51%
  • B+1.10%
  • BB1.54%
  • BB-0.65%
  • BB+0.54%
  • BBB9.69%
  • BBB-13.04%
  • BBB+7.21%
  • CC0.25%
  • NR7.45%
  • Total 100.00%
FootnoteDescription
Footnote*
Investments in investment grade municipal bonds, which are bonds that are rated, at the time of purchase, within the four highest grades assigned by an independent rating agency such as Moody’s, S&P, or Fitch, or an equivalent short-term rating, as applicable, or are unrated by rating agencies but deemed by Lord Abbett to be of comparable quality. Lower rated municipal bonds are rated, at the time of purchase, or an equivalent short-term rating, as applicable, by an independent rating agency or are unrated by rating agencies but deemed by Lord Abbett to be of comparable quality.
Footnote**
Represents percent of total investments, which excludes derivatives.
Credit Ratings Selection [Text Block] Investments in investment grade municipal bonds, which are bonds that are rated, at the time of purchase, within the four highest grades assigned by an independent rating agency such as Moody’s, S&P, or Fitch, or an equivalent short-term rating, as applicable, or are unrated by rating agencies but deemed by Lord Abbett to be of comparable quality. Lower rated municipal bonds are rated, at the time of purchase, or an equivalent short-term rating, as applicable, by an independent rating agency or are unrated by rating agencies but deemed by Lord Abbett to be of comparable quality.
C000188224  
Shareholder Report [Line Items]  
Fund Name Lord Abbett New York Tax Free Fund
Class Name Class F3
Trading Symbol LONYX
Annual or Semi-Annual Statement [Text Block] This semi-annual shareholder report contains important information about the Lord Abbett New York Tax Free Fund for the period of October 1, 2025 to March 31, 2026.
Additional Information [Text Block] You can find additional information about the Fund at lordabbett.com/FundDocuments. You can also request this information by contacting us at 888-522-2388.
Additional Information Phone Number 888-522-2388
Additional Information Website <span style="box-sizing: border-box; color: rgb(0, 0, 0); display: inline; flex-wrap: nowrap; font-size: 13.3333px; font-weight: 400; grid-area: auto; line-height: 20px; margin: 0px; overflow: visible; text-align: left; text-align-last: auto; white-space-collapse: preserve-breaks;">lordabbett.com/FundDocuments</span>
Expenses [Text Block]

What were the Fund costs for the last period?

(based on a hypothetical $10,000 investment)

Table Summary
Class Name
Costs of a $10,000 investment
Costs paid as a percentage of a $10,000 investment
Class F3
$31
0.61%Footnote Reference(a)
FootnoteDescription
Footnote(a)
Annualized.
Expenses Paid, Amount $ 31
Expense Ratio, Percent 0.61% [33]
AssetsNet $ 590,836,462
Holdings Count | Holding 285
InvestmentCompanyPortfolioTurnover 15.00%
Additional Fund Statistics [Text Block]

Key Fund Statistics

 

 (as of March 31, 2026)

Table Summary
Total Net Assets
$590,836,462
# of Portfolio Holdings
285
Portfolio Turnover Rate
15%
Holdings [Text Block]
Table Summary
Portfolio Holdings Presented by Credit Rating S&P or Moody'sFootnote Reference*
%Footnote Reference**
  • A9.18%
  • A-2.40%
  • A+4.83%
  • AA12.51%
  • AA-3.90%
  • AA+14.55%
  • AAA9.76%
  • B0.89%
  • B-0.51%
  • B+1.10%
  • BB1.54%
  • BB-0.65%
  • BB+0.54%
  • BBB9.69%
  • BBB-13.04%
  • BBB+7.21%
  • CC0.25%
  • NR7.45%
  • Total 100.00%
FootnoteDescription
Footnote*
Investments in investment grade municipal bonds, which are bonds that are rated, at the time of purchase, within the four highest grades assigned by an independent rating agency such as Moody’s, S&P, or Fitch, or an equivalent short-term rating, as applicable, or are unrated by rating agencies but deemed by Lord Abbett to be of comparable quality. Lower rated municipal bonds are rated, at the time of purchase, or an equivalent short-term rating, as applicable, by an independent rating agency or are unrated by rating agencies but deemed by Lord Abbett to be of comparable quality.
Footnote**
Represents percent of total investments, which excludes derivatives.
Credit Ratings Selection [Text Block] Investments in investment grade municipal bonds, which are bonds that are rated, at the time of purchase, within the four highest grades assigned by an independent rating agency such as Moody’s, S&P, or Fitch, or an equivalent short-term rating, as applicable, or are unrated by rating agencies but deemed by Lord Abbett to be of comparable quality. Lower rated municipal bonds are rated, at the time of purchase, or an equivalent short-term rating, as applicable, by an independent rating agency or are unrated by rating agencies but deemed by Lord Abbett to be of comparable quality.
C000096847  
Shareholder Report [Line Items]  
Fund Name Lord Abbett New York Tax Free Fund
Class Name Class I
Trading Symbol NYLIX
Annual or Semi-Annual Statement [Text Block] This semi-annual shareholder report contains important information about the Lord Abbett New York Tax Free Fund for the period of October 1, 2025 to March 31, 2026.
Additional Information [Text Block] You can find additional information about the Fund at lordabbett.com/FundDocuments. You can also request this information by contacting us at 888-522-2388.
Additional Information Phone Number 888-522-2388
Additional Information Website <span style="box-sizing: border-box; color: rgb(0, 0, 0); display: inline; flex-wrap: nowrap; font-size: 13.3333px; font-weight: 400; grid-area: auto; line-height: 20px; margin: 0px; overflow: visible; text-align: left; text-align-last: auto; white-space-collapse: preserve-breaks;">lordabbett.com/FundDocuments</span>
Expenses [Text Block]

What were the Fund costs for the last period?

(based on a hypothetical $10,000 investment)

Table Summary
Class Name
Costs of a $10,000 investment
Costs paid as a percentage of a $10,000 investment
Class I
$33
0.65%Footnote Reference(a)
FootnoteDescription
Footnote(a)
Annualized.
Expenses Paid, Amount $ 33
Expense Ratio, Percent 0.65% [34]
AssetsNet $ 590,836,462
Holdings Count | Holding 285
InvestmentCompanyPortfolioTurnover 15.00%
Additional Fund Statistics [Text Block]

Key Fund Statistics

 

 (as of March 31, 2026)

Table Summary
Total Net Assets
$590,836,462
# of Portfolio Holdings
285
Portfolio Turnover Rate
15%
Holdings [Text Block]
Table Summary
Portfolio Holdings Presented by Credit Rating S&P or Moody'sFootnote Reference*
%Footnote Reference**
  • A9.18%
  • A-2.40%
  • A+4.83%
  • AA12.51%
  • AA-3.90%
  • AA+14.55%
  • AAA9.76%
  • B0.89%
  • B-0.51%
  • B+1.10%
  • BB1.54%
  • BB-0.65%
  • BB+0.54%
  • BBB9.69%
  • BBB-13.04%
  • BBB+7.21%
  • CC0.25%
  • NR7.45%
  • Total 100.00%
FootnoteDescription
Footnote*
Investments in investment grade municipal bonds, which are bonds that are rated, at the time of purchase, within the four highest grades assigned by an independent rating agency such as Moody’s, S&P, or Fitch, or an equivalent short-term rating, as applicable, or are unrated by rating agencies but deemed by Lord Abbett to be of comparable quality. Lower rated municipal bonds are rated, at the time of purchase, or an equivalent short-term rating, as applicable, by an independent rating agency or are unrated by rating agencies but deemed by Lord Abbett to be of comparable quality.
Footnote**
Represents percent of total investments, which excludes derivatives.
Credit Ratings Selection [Text Block] Investments in investment grade municipal bonds, which are bonds that are rated, at the time of purchase, within the four highest grades assigned by an independent rating agency such as Moody’s, S&P, or Fitch, or an equivalent short-term rating, as applicable, or are unrated by rating agencies but deemed by Lord Abbett to be of comparable quality. Lower rated municipal bonds are rated, at the time of purchase, or an equivalent short-term rating, as applicable, by an independent rating agency or are unrated by rating agencies but deemed by Lord Abbett to be of comparable quality.
C000155633  
Shareholder Report [Line Items]  
Fund Name Lord Abbett Short Duration High Income Municipal Bond Fund
Class Name Class A
Trading Symbol SDHAX
Annual or Semi-Annual Statement [Text Block] This semi-annual shareholder report contains important information about the Lord Abbett Short Duration High Income Municipal Bond Fund for the period of October 1, 2025 to March 31, 2026.
Additional Information [Text Block] You can find additional information about the Fund at lordabbett.com/FundDocuments. You can also request this information by contacting us at 888-522-2388.
Additional Information Phone Number 888-522-2388
Additional Information Website <span style="box-sizing: border-box; color: rgb(0, 0, 0); display: inline; flex-wrap: nowrap; font-size: 13.3333px; font-weight: 400; grid-area: auto; line-height: 20px; margin: 0px; overflow: visible; text-align: left; text-align-last: auto; white-space-collapse: preserve-breaks;">lordabbett.com/FundDocuments</span>
Expenses [Text Block]

What were the Fund costs for the last period?

(based on a hypothetical $10,000 investment)

Table Summary
Class Name
Costs of a $10,000 investment
Costs paid as a percentage of a $10,000 investment
Class A
$33
0.65%Footnote Reference(a)
FootnoteDescription
Footnote(a)
Annualized.
Expenses Paid, Amount $ 33
Expense Ratio, Percent 0.65% [35]
AssetsNet $ 2,787,862,610
Holdings Count | Holding 528
InvestmentCompanyPortfolioTurnover 19.00%
Additional Fund Statistics [Text Block]

Key Fund Statistics

 

 (as of March 31, 2026)

Table Summary
Total Net Assets
$2,787,862,610
# of Portfolio Holdings
528
Portfolio Turnover Rate
19%
Holdings [Text Block]
Table Summary
Portfolio Holdings Presented by Credit Rating S&P or Moody'sFootnote Reference*
%Footnote Reference**
  • A5.45%
  • A-2.70%
  • A+3.65%
  • AA3.71%
  • AA-2.72%
  • AA+1.92%
  • AAA0.91%
  • B1.70%
  • B-1.34%
  • B+3.73%
  • BB3.82%
  • BB-2.65%
  • BB+13.19%
  • BBB8.98%
  • BBB-6.03%
  • BBB+7.69%
  • CC0.45%
  • CCC+0.63%
  • NR28.73%
  • Total 100.00%
FootnoteDescription
Footnote*
Investments in investment grade municipal bonds, which are bonds that are rated, at the time of purchase, within the four highest grades assigned by an independent rating agency such as Moody’s, S&P, or Fitch, or an equivalent short-term rating, as applicable, or are unrated by rating agencies but deemed by Lord Abbett to be of comparable quality. Lower rated municipal bonds are rated, at the time of purchase, or an equivalent short-term rating, as applicable, by an independent rating agency or are unrated by rating agencies but deemed by Lord Abbett to be of comparable quality.
Footnote**
Represents percent of total investments, which excludes derivatives.
Credit Ratings Selection [Text Block] Investments in investment grade municipal bonds, which are bonds that are rated, at the time of purchase, within the four highest grades assigned by an independent rating agency such as Moody’s, S&P, or Fitch, or an equivalent short-term rating, as applicable, or are unrated by rating agencies but deemed by Lord Abbett to be of comparable quality. Lower rated municipal bonds are rated, at the time of purchase, or an equivalent short-term rating, as applicable, by an independent rating agency or are unrated by rating agencies but deemed by Lord Abbett to be of comparable quality.
C000155634  
Shareholder Report [Line Items]  
Fund Name Lord Abbett Short Duration High Income Municipal Bond Fund
Class Name Class C
Trading Symbol SDHCX
Annual or Semi-Annual Statement [Text Block] This semi-annual shareholder report contains important information about the Lord Abbett Short Duration High Income Municipal Bond Fund for the period of October 1, 2025 to March 31, 2026.
Additional Information [Text Block] You can find additional information about the Fund at lordabbett.com/FundDocuments. You can also request this information by contacting us at 888-522-2388.
Additional Information Phone Number 888-522-2388
Additional Information Website <span style="box-sizing: border-box; color: rgb(0, 0, 0); display: inline; flex-wrap: nowrap; font-size: 13.3333px; font-weight: 400; grid-area: auto; line-height: 20px; margin: 0px; overflow: visible; text-align: left; text-align-last: auto; white-space-collapse: preserve-breaks;">lordabbett.com/FundDocuments</span>
Expenses [Text Block]

What were the Fund costs for the last period?

(based on a hypothetical $10,000 investment)

Table Summary
Class Name
Costs of a $10,000 investment
Costs paid as a percentage of a $10,000 investment
Class C
$66
1.32%Footnote Reference(a)
FootnoteDescription
Footnote(a)
Annualized.
Expenses Paid, Amount $ 66
Expense Ratio, Percent 1.32% [36]
AssetsNet $ 2,787,862,610
Holdings Count | Holding 528
InvestmentCompanyPortfolioTurnover 19.00%
Additional Fund Statistics [Text Block]

Key Fund Statistics

 

 (as of March 31, 2026)

Table Summary
Total Net Assets
$2,787,862,610
# of Portfolio Holdings
528
Portfolio Turnover Rate
19%
Holdings [Text Block]
Table Summary
Portfolio Holdings Presented by Credit Rating S&P or Moody'sFootnote Reference*
%Footnote Reference**
  • A5.45%
  • A-2.70%
  • A+3.65%
  • AA3.71%
  • AA-2.72%
  • AA+1.92%
  • AAA0.91%
  • B1.70%
  • B-1.34%
  • B+3.73%
  • BB3.82%
  • BB-2.65%
  • BB+13.19%
  • BBB8.98%
  • BBB-6.03%
  • BBB+7.69%
  • CC0.45%
  • CCC+0.63%
  • NR28.73%
  • Total 100.00%
FootnoteDescription
Footnote*
Investments in investment grade municipal bonds, which are bonds that are rated, at the time of purchase, within the four highest grades assigned by an independent rating agency such as Moody’s, S&P, or Fitch, or an equivalent short-term rating, as applicable, or are unrated by rating agencies but deemed by Lord Abbett to be of comparable quality. Lower rated municipal bonds are rated, at the time of purchase, or an equivalent short-term rating, as applicable, by an independent rating agency or are unrated by rating agencies but deemed by Lord Abbett to be of comparable quality.
Footnote**
Represents percent of total investments, which excludes derivatives.
Credit Ratings Selection [Text Block] Investments in investment grade municipal bonds, which are bonds that are rated, at the time of purchase, within the four highest grades assigned by an independent rating agency such as Moody’s, S&P, or Fitch, or an equivalent short-term rating, as applicable, or are unrated by rating agencies but deemed by Lord Abbett to be of comparable quality. Lower rated municipal bonds are rated, at the time of purchase, or an equivalent short-term rating, as applicable, by an independent rating agency or are unrated by rating agencies but deemed by Lord Abbett to be of comparable quality.
C000155635  
Shareholder Report [Line Items]  
Fund Name Lord Abbett Short Duration High Income Municipal Bond Fund
Class Name Class F
Trading Symbol SDHFX
Annual or Semi-Annual Statement [Text Block] This semi-annual shareholder report contains important information about the Lord Abbett Short Duration High Income Municipal Bond Fund for the period of October 1, 2025 to March 31, 2026.
Additional Information [Text Block] You can find additional information about the Fund at lordabbett.com/FundDocuments. You can also request this information by contacting us at 888-522-2388.
Additional Information Phone Number 888-522-2388
Additional Information Website <span style="box-sizing: border-box; color: rgb(0, 0, 0); display: inline; flex-wrap: nowrap; font-size: 13.3333px; font-weight: 400; grid-area: auto; line-height: 20px; margin: 0px; overflow: visible; text-align: left; text-align-last: auto; white-space-collapse: preserve-breaks;">lordabbett.com/FundDocuments</span>
Expenses [Text Block]

What were the Fund costs for the last period?

(based on a hypothetical $10,000 investment)

Table Summary
Class Name
Costs of a $10,000 investment
Costs paid as a percentage of a $10,000 investment
Class F
$28
0.55%Footnote Reference(a)
FootnoteDescription
Footnote(a)
Annualized.
Expenses Paid, Amount $ 28
Expense Ratio, Percent 0.55% [37]
AssetsNet $ 2,787,862,610
Holdings Count | Holding 528
InvestmentCompanyPortfolioTurnover 19.00%
Additional Fund Statistics [Text Block]

Key Fund Statistics

 

 (as of March 31, 2026)

Table Summary
Total Net Assets
$2,787,862,610
# of Portfolio Holdings
528
Portfolio Turnover Rate
19%
Holdings [Text Block]
Table Summary
Portfolio Holdings Presented by Credit Rating S&P or Moody'sFootnote Reference*
%Footnote Reference**
  • A5.45%
  • A-2.70%
  • A+3.65%
  • AA3.71%
  • AA-2.72%
  • AA+1.92%
  • AAA0.91%
  • B1.70%
  • B-1.34%
  • B+3.73%
  • BB3.82%
  • BB-2.65%
  • BB+13.19%
  • BBB8.98%
  • BBB-6.03%
  • BBB+7.69%
  • CC0.45%
  • CCC+0.63%
  • NR28.73%
  • Total 100.00%
FootnoteDescription
Footnote*
Investments in investment grade municipal bonds, which are bonds that are rated, at the time of purchase, within the four highest grades assigned by an independent rating agency such as Moody’s, S&P, or Fitch, or an equivalent short-term rating, as applicable, or are unrated by rating agencies but deemed by Lord Abbett to be of comparable quality. Lower rated municipal bonds are rated, at the time of purchase, or an equivalent short-term rating, as applicable, by an independent rating agency or are unrated by rating agencies but deemed by Lord Abbett to be of comparable quality.
Footnote**
Represents percent of total investments, which excludes derivatives.
Credit Ratings Selection [Text Block] Investments in investment grade municipal bonds, which are bonds that are rated, at the time of purchase, within the four highest grades assigned by an independent rating agency such as Moody’s, S&P, or Fitch, or an equivalent short-term rating, as applicable, or are unrated by rating agencies but deemed by Lord Abbett to be of comparable quality. Lower rated municipal bonds are rated, at the time of purchase, or an equivalent short-term rating, as applicable, by an independent rating agency or are unrated by rating agencies but deemed by Lord Abbett to be of comparable quality.
C000188229  
Shareholder Report [Line Items]  
Fund Name Lord Abbett Short Duration High Income Municipal Bond Fund
Class Name Class F3
Trading Symbol HYMQX
Annual or Semi-Annual Statement [Text Block] This semi-annual shareholder report contains important information about the Lord Abbett Short Duration High Income Municipal Bond Fund for the period of October 1, 2025 to March 31, 2026.
Additional Information [Text Block] You can find additional information about the Fund at lordabbett.com/FundDocuments. You can also request this information by contacting us at 888-522-2388.
Additional Information Phone Number 888-522-2388
Additional Information Website <span style="box-sizing: border-box; color: rgb(0, 0, 0); display: inline; flex-wrap: nowrap; font-size: 13.3333px; font-weight: 400; grid-area: auto; line-height: 20px; margin: 0px; overflow: visible; text-align: left; text-align-last: auto; white-space-collapse: preserve-breaks;">lordabbett.com/FundDocuments</span>
Expenses [Text Block]

What were the Fund costs for the last period?

(based on a hypothetical $10,000 investment)

Table Summary
Class Name
Costs of a $10,000 investment
Costs paid as a percentage of a $10,000 investment
Class F3
$20
0.40%Footnote Reference(a)
FootnoteDescription
Footnote(a)
Annualized.
Expenses Paid, Amount $ 20
Expense Ratio, Percent 0.40% [38]
AssetsNet $ 2,787,862,610
Holdings Count | Holding 528
InvestmentCompanyPortfolioTurnover 19.00%
Additional Fund Statistics [Text Block]

Key Fund Statistics

 

 (as of March 31, 2026)

Table Summary
Total Net Assets
$2,787,862,610
# of Portfolio Holdings
528
Portfolio Turnover Rate
19%
Holdings [Text Block]
Table Summary
Portfolio Holdings Presented by Credit Rating S&P or Moody'sFootnote Reference*
%Footnote Reference**
  • A5.45%
  • A-2.70%
  • A+3.65%
  • AA3.71%
  • AA-2.72%
  • AA+1.92%
  • AAA0.91%
  • B1.70%
  • B-1.34%
  • B+3.73%
  • BB3.82%
  • BB-2.65%
  • BB+13.19%
  • BBB8.98%
  • BBB-6.03%
  • BBB+7.69%
  • CC0.45%
  • CCC+0.63%
  • NR28.73%
  • Total 100.00%
FootnoteDescription
Footnote*
Investments in investment grade municipal bonds, which are bonds that are rated, at the time of purchase, within the four highest grades assigned by an independent rating agency such as Moody’s, S&P, or Fitch, or an equivalent short-term rating, as applicable, or are unrated by rating agencies but deemed by Lord Abbett to be of comparable quality. Lower rated municipal bonds are rated, at the time of purchase, or an equivalent short-term rating, as applicable, by an independent rating agency or are unrated by rating agencies but deemed by Lord Abbett to be of comparable quality.
Footnote**
Represents percent of total investments, which excludes derivatives.
Credit Ratings Selection [Text Block] Investments in investment grade municipal bonds, which are bonds that are rated, at the time of purchase, within the four highest grades assigned by an independent rating agency such as Moody’s, S&P, or Fitch, or an equivalent short-term rating, as applicable, or are unrated by rating agencies but deemed by Lord Abbett to be of comparable quality. Lower rated municipal bonds are rated, at the time of purchase, or an equivalent short-term rating, as applicable, by an independent rating agency or are unrated by rating agencies but deemed by Lord Abbett to be of comparable quality.
C000155636  
Shareholder Report [Line Items]  
Fund Name Lord Abbett Short Duration High Income Municipal Bond Fund
Class Name Class I
Trading Symbol SDHIX
Annual or Semi-Annual Statement [Text Block] This semi-annual shareholder report contains important information about the Lord Abbett Short Duration High Income Municipal Bond Fund for the period of October 1, 2025 to March 31, 2026.
Additional Information [Text Block] You can find additional information about the Fund at lordabbett.com/FundDocuments. You can also request this information by contacting us at 888-522-2388.
Additional Information Phone Number 888-522-2388
Additional Information Website <span style="box-sizing: border-box; color: rgb(0, 0, 0); display: inline; flex-wrap: nowrap; font-size: 13.3333px; font-weight: 400; grid-area: auto; line-height: 20px; margin: 0px; overflow: visible; text-align: left; text-align-last: auto; white-space-collapse: preserve-breaks;">lordabbett.com/FundDocuments</span>
Expenses [Text Block]

What were the Fund costs for the last period?

(based on a hypothetical $10,000 investment)

Table Summary
Class Name
Costs of a $10,000 investment
Costs paid as a percentage of a $10,000 investment
Class I
$23
0.45%Footnote Reference(a)
FootnoteDescription
Footnote(a)
Annualized.
Expenses Paid, Amount $ 23
Expense Ratio, Percent 0.45% [39]
AssetsNet $ 2,787,862,610
Holdings Count | Holding 528
InvestmentCompanyPortfolioTurnover 19.00%
Additional Fund Statistics [Text Block]

Key Fund Statistics

 

 (as of March 31, 2026)

Table Summary
Total Net Assets
$2,787,862,610
# of Portfolio Holdings
528
Portfolio Turnover Rate
19%
Holdings [Text Block]
Table Summary
Portfolio Holdings Presented by Credit Rating S&P or Moody'sFootnote Reference*
%Footnote Reference**
  • A5.45%
  • A-2.70%
  • A+3.65%
  • AA3.71%
  • AA-2.72%
  • AA+1.92%
  • AAA0.91%
  • B1.70%
  • B-1.34%
  • B+3.73%
  • BB3.82%
  • BB-2.65%
  • BB+13.19%
  • BBB8.98%
  • BBB-6.03%
  • BBB+7.69%
  • CC0.45%
  • CCC+0.63%
  • NR28.73%
  • Total 100.00%
FootnoteDescription
Footnote*
Investments in investment grade municipal bonds, which are bonds that are rated, at the time of purchase, within the four highest grades assigned by an independent rating agency such as Moody’s, S&P, or Fitch, or an equivalent short-term rating, as applicable, or are unrated by rating agencies but deemed by Lord Abbett to be of comparable quality. Lower rated municipal bonds are rated, at the time of purchase, or an equivalent short-term rating, as applicable, by an independent rating agency or are unrated by rating agencies but deemed by Lord Abbett to be of comparable quality.
Footnote**
Represents percent of total investments, which excludes derivatives.
Credit Ratings Selection [Text Block] Investments in investment grade municipal bonds, which are bonds that are rated, at the time of purchase, within the four highest grades assigned by an independent rating agency such as Moody’s, S&P, or Fitch, or an equivalent short-term rating, as applicable, or are unrated by rating agencies but deemed by Lord Abbett to be of comparable quality. Lower rated municipal bonds are rated, at the time of purchase, or an equivalent short-term rating, as applicable, by an independent rating agency or are unrated by rating agencies but deemed by Lord Abbett to be of comparable quality.
[1] Annualized.
[2] Annualized.
[3] Annualized.
[4] Annualized.
[5] Annualized.
[6] Annualized.
[7] Annualized.
[8] Annualized.
[9] Annualized.
[10] Annualized.
[11] Annualized.
[12] Annualized.
[13] Annualized.
[14] Annualized.
[15] Annualized.
[16] Annualized.
[17] Annualized.
[18] Annualized.
[19] Annualized.
[20] Annualized.
[21] Annualized.
[22] Annualized.
[23] Annualized.
[24] Annualized.
[25] Annualized.
[26] Annualized.
[27] Annualized.
[28] Annualized.
[29] Annualized.
[30] Annualized.
[31] Annualized.
[32] Annualized.
[33] Annualized.
[34] Annualized.
[35] Annualized.
[36] Annualized.
[37] Annualized.
[38] Annualized.
[39] Annualized.