v3.26.1
Annual Fund Operating Expenses
Aug. 20, 2026
Thornburg Investment Income Builder Fund - Class A  
Prospectus [Line Items]  
Management Fees (as a percentage of Assets) 0.69%
Distribution and Service (12b-1) Fees 0.25%
Other Expenses (as a percentage of Assets): 0.18%
Acquired Fund Fees and Expenses 0.03%
Expenses (as a percentage of Assets) 1.15% [1]
Fee Waiver or Reimbursement [2]
Net Expenses (as a percentage of Assets) 1.15% [1]
Thornburg Investment Income Builder Fund - Class C  
Prospectus [Line Items]  
Management Fees (as a percentage of Assets) 0.69%
Distribution and Service (12b-1) Fees 1.00%
Other Expenses (as a percentage of Assets): 0.18%
Acquired Fund Fees and Expenses 0.03%
Expenses (as a percentage of Assets) 1.90% [1]
Fee Waiver or Reimbursement [2]
Net Expenses (as a percentage of Assets) 1.90% [1]
Thornburg Investment Income Builder Fund - Class I  
Prospectus [Line Items]  
Management Fees (as a percentage of Assets) 0.69%
Distribution and Service (12b-1) Fees 0.00%
Other Expenses (as a percentage of Assets): 0.19%
Acquired Fund Fees and Expenses 0.03%
Expenses (as a percentage of Assets) 0.91% [1]
Fee Waiver or Reimbursement [2]
Net Expenses (as a percentage of Assets) 0.91% [1]
Thornburg Investment Income Builder Fund - Class R6  
Prospectus [Line Items]  
Management Fees (as a percentage of Assets) 0.69%
Distribution and Service (12b-1) Fees 0.00%
Other Expenses (as a percentage of Assets): 0.13%
Acquired Fund Fees and Expenses 0.03%
Expenses (as a percentage of Assets) 0.85% [1]
Fee Waiver or Reimbursement (0.02%) [2]
Net Expenses (as a percentage of Assets) 0.83% [1]
Fee Waiver or Reimbursement over Assets, Date of Termination February 1, 2027
Thornburg Summit Fund - Class A  
Prospectus [Line Items]  
Management Fees (as a percentage of Assets) 0.75%
Distribution and Service (12b-1) Fees 0.25%
Other Expenses (as a percentage of Assets): 0.82%
Acquired Fund Fees and Expenses 0.01%
Expenses (as a percentage of Assets) 1.83% [3]
Fee Waiver or Reimbursement (0.88%) [4]
Net Expenses (as a percentage of Assets) 0.95% [3]
Fee Waiver or Reimbursement over Assets, Date of Termination February 1, 2027
Thornburg Summit Fund - Class I  
Prospectus [Line Items]  
Management Fees (as a percentage of Assets) 0.75%
Distribution and Service (12b-1) Fees 0.00%
Other Expenses (as a percentage of Assets): 0.45%
Acquired Fund Fees and Expenses 0.01%
Expenses (as a percentage of Assets) 1.21% [3]
Fee Waiver or Reimbursement (0.51%) [4]
Net Expenses (as a percentage of Assets) 0.70% [3]
Fee Waiver or Reimbursement over Assets, Date of Termination February 1, 2027
[1] The Total Annual Fund Operating Expenses and Total Annual Fund Operating Expenses After Fee Waiver/Expense Reimbursement do not match the Ratios to Average Net Assets shown in the Financial Highlights section of the Prospectus, which reflect the operating expenses of the Fund and do not include acquired fund fees and expenses (‘AFFE’). AFFE are expenses incurred indirectly by other investment companies in which the Fund holds shares, are not direct costs paid by Fund shareholders, and are not used to calculate the Fund’s net asset value.
[2] Thornburg Investment Management, Inc. (“Thornburg”) has contractually agreed to waive fees and reimburse expenses incurred by the Fund so that actual Class R6 expenses (excluding taxes, interest expenses, acquired fund fees and expenses, brokerage commissions, borrowing costs, expenses relating to short sales, and unusual expenses such as contingency fees or litigation costs) do not exceed 0.80%. The agreement to waive fees and reimburse expenses may be terminated by the Fund’s Trustees at any time, but may not be terminated by Thornburg before February 1, 2027, unless Thornburg ceases to be the investment advisor of the Fund prior to that date. Thornburg may recoup amounts waived or reimbursed during the Fund’s fiscal year if actual expenses fall below the expense cap during that same fiscal year.
[3] The Total Annual Fund Operating Expenses and Total Annual Fund Operating Expenses After Fee Waiver/Expense Reimbursement do not match the Ratios to Average Net Assets shown in the Financial Highlights section of the Prospectus, which reflect the operating expenses of the Fund and do not include acquired fund fees and expenses (‘AFFE’). AFFE are expenses incurred indirectly by other investment companies in which the Fund holds shares, are not direct costs paid by Fund shareholders, and are not used to calculate the Fund’s net asset value.
[4] Thornburg Investment Management, Inc. (“Thornburg”) has contractually agreed to waive fees and reimburse expenses incurred by the Fund so that actual Class A and Class I expenses (excluding taxes, interest expenses, acquired fund fees and expenses, brokerage commissions, borrowing costs, expenses relating to short sales, and unusual expenses such as contingency fees or litigation costs) do not exceed 0.94% and 0.69%, respectively. The agreement to waive fees and reimburse expenses may be terminated by the Fund’s Trustees at any time, but may not be terminated by Thornburg before February 1, 2027, unless Thornburg ceases to be the investment advisor of the Fund prior to that date. Thornburg may recoup amounts waived or reimbursed during the Fund’s fiscal year if, after taking the recoupment into account, the Fund’s actual expenses fall below the expense cap during that same fiscal year.