Exhibit 99.1

SLM Student Loan Trust 2013-4

Monthly Servicing Report

Distribution Date 09/25/2026

Collection Period 08/01/2026 - 08/31/2026

Navient Funding, LLC - Depositor

Navient Solutions -  Master Servicer and Administrator

Deutsche Bank National Trust Company - Indenture Trustee

Deutsche Bank Trust Company Americas - Eligible Lender Trustee

Navient Funding - Excess Distribution Certificateholder

Page 1 of 9
Trust 2013-4 Monthly Servicing Report: Collection Period 08/01/2026 - 08/31/2026, Distribution Date 09/25/2026
I.
Deal Parameters

A
Student Loan Portfolio Characteristics
  
08/15/2013
    
07/31/2026
    
08/31/2026
  

Principal Balance  
$
721,402,856.22
    
$
117,825,882.38
    
$
117,071,776.48
  

Interest to be Capitalized Balance    
12,923,603.00
      
1,539,656.25
      
1,529,858.34
  

Pool Balance  
$
734,326,459.22
    
$
119,365,538.63
    
$
118,601,634.82
  

Specified Reserve Account Balance    
3,744,487.00
      
- N/A -
      
- N/A -
  

Adjusted Pool(1)  
$
738,070,946.22
    
$
119,365,538.63
    
$
118,601,634.82
  

Weighted Average Coupon (WAC)
    
6.28%

   
6.85%

   
6.85%


Number of Loans    
163,648
      
16,959
      
16,787
  

Aggregate Outstanding Principal Balance - Tbill            
-
      
-
  

Aggregate Outstanding Principal Balance - SOFR          
$
119,365,538.63
    
$
118,601,634.82
  

Pool Factor            
0.159388373
      
0.158368335
  

Since Issued Constant Prepayment Rate            
(71.72)%

   
(71.51)%


(1) The Specified Reserve Account balance is included in the Adjusted Pool until the Pool Balance is less than or equal to 40% of the original pool.

B
Debt Securities
Cusip/Isin
  
08/25/2026
    
09/25/2026
  
  A
78448AAA1
  
$
97,588,627.34
    
$
96,815,618.47
  
  B
78448AAD5
  
$
20,600,000.00
    
$
20,600,000.00
  

C
Account Balances
  
08/25/2026
    
09/25/2026
  

Reserve Account Balance  
$
748,897.00
    
$
748,897.00
  

Capitalized Interest Account Balance    
-
      
-
  

Floor Income Rebate Account  
$
272,095.19
    
$
87,107.72
  

Supplemental Loan Purchase Account    
-
      
-
  

D
Asset / Liability
  
08/25/2026
    
09/25/2026
  

Adjusted Pool Balance + Supplemental Loan Purchase  
$
119,365,538.63
    
$
118,601,634.82
  

Total Notes  
$
118,188,627.34
    
$
117,415,618.47
  

Difference  
$
1,176,911.29
    
$
1,186,016.35
  

Parity Ratio    
1.00996
      
1.01010
  

Page 2 of 9
Trust 2013-4 Monthly Servicing Report: Collection Period 08/01/2026 - 08/31/2026, Distribution Date 09/25/2026
II.
Trust Activity 08/01/2026 through 08/31/2026

A
Student Loan Principal Receipts
      
 
Borrower Principal
    
266,711.49
  
 
Guarantor Principal
    
642,988.36
  
 
Consolidation Activity Principal
    
138,419.67
  
 
Seller Principal Reimbursement
    
-
  
 
Servicer Principal Reimbursement
    
(83.15)
  
 
Rejected Claim Repurchased Principal
    
-
  
 
Other Principal Deposits
    
-
  
 
Total Principal Receipts
  
$
1,048,036.37
  
B
Student Loan Interest Receipts
        
 
Borrower Interest
    
169,048.11
  
 
Guarantor Interest
    
22,150.97
  
 
Consolidation Activity Interest
    
5,843.89
  
 
Special Allowance Payments
    
63,585.22
  
 
Interest Subsidy Payments
    
64,529.87
  
 
Seller Interest Reimbursement
    
0.00
  
 
Servicer Interest Reimbursement
    
0.00

 
Rejected Claim Repurchased Interest
    
0.00
  
 
Other Interest Deposits
    
5,997.47
  
 
Total Interest Receipts
  
$
331,155.53
  
C
Reserves in Excess of Requirement
  

-
  
D
Investment Income
  
$
8,559.08
  
E
Funds Borrowed from Next Collection Period
    
-
  
F
Funds Repaid from Prior Collection Period
    
-
  
G
Loan Sale or Purchase Proceeds
    
-
  
H
Initial Deposits to Collection Account
    
-
  
I
Excess Transferred from Other Accounts
   $
272,095.19
  
J
Other Deposits
    
-
  
K
Funds Released from Capitalized Interest Account
    
-
  
L
Less:  Funds Previously Remitted:
        
 
Servicing Fees to Servicer
    
-
  
 
Consolidation Loan Rebate Fees to Dept. of Education
    
-
  
 
Floor Income Rebate Fees to Dept. of Education
   $
(273,654.01)

 
Funds Allocated to the Floor Income Rebate Account
  
$
(87,107.72)

M
AVAILABLE FUNDS
  
$
1,299,084.44
  
N
Non-Cash Principal Activity During Collection Period
  
$
(293,930.47)

O
Non-Reimbursable Losses During Collection Period
  
$
16,136.12
  
P
Aggregate Purchased Amounts by the Depositor, Servicer or Seller
  

-
  
Q
Aggregate Loan Substitutions
    
-
  

Page 3 of 9
Trust 2013-4 Monthly Servicing Report: Collection Period 08/01/2026 - 08/31/2026, Distribution Date 09/25/2026
III.
2013-4 Portfolio Characteristics

     
08/31/2026
    
07/31/2026
  
      
Wtd Avg Coupon
    
# Loans
    
Principal
    
% of Principal
    
Wtd Avg Coupon
    
# Loans
    
Principal
    
% of Principal
  
INTERIM:
IN SCHOOL
    
6.73%

   
18
    
$
153,417.00
      
0.131%

   
6.73%

   
18
    
$
153,417.00
      
0.130%


DEFERMENT    
6.71%

   
849
    
$
6,312,710.54
      
5.392%

   
6.69%

   
851
    
$
6,254,616.09
      
5.308%

                                                                   
REPAYMENT:
CURRENT
    
6.85%

   
11,810
    
$
75,948,974.18
      
64.874%

   
6.84%

   
11,768
    
$
75,317,922.73
      
63.923%


31-60 DAYS DELINQUENT    
6.86%

   
515
    
$
4,318,254.77
      
3.689%

   
6.92%

   
557
    
$
4,859,203.37
      
4.124%


61-90 DAYS DELINQUENT    
6.93%

   
404
    
$
3,947,648.62
      
3.372%

   
6.73%

   
379
    
$
3,050,615.57
      
2.589%


91-120 DAYS DELINQUENT    
6.76%

   
291
    
$
2,557,945.34
      
2.185%

   
6.87%

   
249
    
$
2,234,564.66
      
1.896%


> 120 DAYS DELINQUENT    
6.85%

   
758
    
$
6,752,889.99
      
5.768%

   
6.88%

   
750
    
$
6,583,371.36
      
5.587%

                                                                   

FORBEARANCE    
6.91%

   
1,989
    
$
15,839,129.83
      
13.529%

   
6.90%

   
2,193
    
$
17,892,515.02
      
15.186%


CLAIMS IN PROCESS
   
6.89%

   
153
    
$
1,240,806.21
      
1.060%

   
6.80%

   
194
    
$
1,479,656.58
      
1.256%

                                                                   
TOTAL
              
16,787
    
$
117,071,776.48
      
100.00%

           
16,959
    
$
117,825,882.38
      
100.00%


* Percentages may not total 100% due to rounding

Page 4 of 9
Trust 2013-4 Monthly Servicing Report: Collection Period 08/01/2026 - 08/31/2026, Distribution Date 09/25/2026
IV.
2013-4 Portfolio Characteristics (cont’d)

   
08/31/2026
    
07/31/2026
  
Pool Balance
  
$
118,601,634.82
    
$
119,365,538.63
  
Outstanding Borrower Accrued Interest
  
$
6,984,252.63
    
$
6,853,454.81
  
Borrower Accrued Interest to be Capitalized
  
$
1,529,858.34
    
$
1,539,656.25
  
Borrower Accrued Interest >30 Days Delinquent
  
$
678,789.95
    
$
629,125.31
  
Total # Loans
    
16,787
      
16,959
  
Total # Borrowers
    
5,317
      
5,370
  
Weighted Average Coupon
    
6.85%

   
6.85%

Weighted Average Remaining Term
    
200.96
      
199.99
  
Non-Reimbursable Losses
  
$
16,136.12
    
$
16,562.83
  
Cumulative Non-Reimbursable Losses
  
$
2,944,584.59
    
$
2,928,448.47
  
Since Issued Constant Prepayment Rate (CPR)
    
-71.51 %

   
-71.72 %

Loan Substitutions
    
-
      
-
  
Cumulative Loan Substitutions
    
-
      
-
  
Rejected Claim Repurchases
    
-
      
-
  
Cumulative Rejected Claim Repurchases
  
$
145,788.07
    
$
145,788.07
  
Unpaid Primary Servicing Fees
    
-
      
-
  
Unpaid Administration Fees
    
-
      
-
  
Unpaid Carryover Servicing Fees
    
-
      
-
  
Note Principal Shortfall
  

-
     $
16,744.10
  
Note Interest Shortfall
    
-
      
-
  
Unpaid Interest Carryover
    
-
      
-
  
Non-Cash Principal Activity - Capitalized Interest
  
$
309,994.13
    
$
389,876.89
  
Borrower Interest Accrued
  
$
656,152.13
    
$
660,919.38
  
Interest Subsidy Payments Accrued
  
$
19,715.48
    
$
20,067.33
  
Special Allowance Payments Accrued
  
$
25,317.68
    
$
24,660.92
  

Page 5 of 9
Trust 2013-4 Monthly Servicing Report: Collection Period 08/01/2026 - 08/31/2026, Distribution Date 09/25/2026
V.
2013-4 Portfolio Statistics by School and Program

A
LOAN TYPE
  
Weighted
Average Coupon
    
# LOANS
    
$ AMOUNT
      
%*


- GSL (1) - Subsidized    
6.63%

   
8,969
      
42,775,641.08
      
36.538%


- GSL - Unsubsidized    
6.68%

   
7,360
      
61,818,834.11
      
52.804%


- PLUS (2) Loans    
8.45%

   
458
      
12,477,301.29
      
10.658%


- SLS (3) Loans
   
0.00%

   
0
      
-
      
0.000%


- Consolidation Loans    
0.00%

   
0
      
-
      
0.000%


Total    
6.85%

   
16,787
    
$
117,071,776.48
      
100.000%


B
SCHOOL TYPE
  
Weighted
Average Coupon
    
# LOANS
    
$ AMOUNT
      
%*


- Four Year    
6.87%

   
14,818
      
108,297,900.11
      
92.506%


- Two Year    
6.65%

   
1,586
      
6,981,368.82
      
5.963%


- Technical    
6.66%

   
383
      
1,792,507.55
      
1.531%


- Other    
0.00%

   
0
      
-
      
0.000%


Total    
6.85%

   
16,787
    
$
117,071,776.48
      
100.000%


*Percentages may not total 100% due to rounding.

(1)
Guaranteed Stafford Loan

(2)
Parent Loans for Undergraduate Students

(3)
Supplemental Loans to Students.  The Unsubsidized Stafford Loan program replaced the SLS program on July 1, 1994.

Page 6 of 9
Trust 2013-4 Monthly Servicing Report: Collection Period 08/01/2026 - 08/31/2026, Distribution Date 09/25/2026
VI.
2013-4 Waterfall for Distributions

     
Paid
    
Remaining
Funds Balance
  
Total Available Funds
        
$
1,299,084.44
  
A
 Trustee Fees
     -
    $
 1,299,084.44
 
B
Primary Servicing Fee
  
$
27,207.18
    
$
1,271,877.26
  
C
Administration Fee
  
$
6,667.00
    
$
1,265,210.26
  
D
Class A Noteholders’ Interest Distribution Amount
  
$
361,993.55
    
$
903,216.71
  
E
Class B Noteholders’ Interest Distribution Amount
  
$
93,265.22
    
$
809,951.49
  
F
Reserve Account Reinstatement
    
-
    
$
809,951.49
  
G
Class A Noteholders’ Principal Distribution Amount
  
$
773,008.87
     $
36,942.62
  
H
Class B Noteholders’ Principal Distribution Amount
    
-
     $
36,942.62
  
I
Unpaid Expenses of The Trustees
    
-
     $
36,942.62
  
J
Carryover Servicing Fee
    
-
     $
36,942.62
  
K
Remaining Amounts to the Noteholders after the first auction date
    
-
     $
36,942.62
  
L
Excess Distribution Certificateholder
   $
36,942.62
      
-
  

Waterfall Triggers
      
A
Student Loan Principal Outstanding
  
$
117,071,776.48
  
B
Interest to be Capitalized
  
$
1,529,858.34
  
C
Capitalized Interest Account Balance
    
-
  
D
Reserve Account Balance (after any reinstatement)
  
$
748,897.00
  
E
Less:  Specified Reserve Account Balance
  
$
(748,897.00)

F
Total
  
$
118,601,634.82
  
G
Class A Notes Outstanding (after application of available funds)
  
$
96,815,618.47
  
H
Insolvency Event or Event of Default Under Indenture
     N

I
Available Funds Applied to Class A Noteholders’ Distribution Amount Before Any Amounts are Applied to the Class B Noteholders’ Distribution Amount (G>F or H=Y)
     N


Page 7 of 9
Trust 2013-4 Monthly Servicing Report: Collection Period 08/01/2026 - 08/31/2026, Distribution Date 09/25/2026
VII.
2013-4 Distributions

Distribution Amounts

     A

   B

Cusip/Isin
  
78448AAA1
    
78448AAD5
  
Beginning Balance
  
$
97,588,627.34
    
$
20,600,000.00
  
Index
  
SOFR
    
SOFR
  
Spread/Fixed Rate
    
0.55%

   
1.50%

Record Date (Days Prior to Distribution)
  
1 NEW YORK BUSINESS DAY
    
1 NEW YORK BUSINESS DAY
  
Accrual Period Begin
  
8/25/2026
    
8/25/2026
  
Accrual Period End
  
9/25/2026
    
9/25/2026
  
Daycount Fraction
    
0.08611111
      
0.08611111
  
Interest Rate*
    
4.30767%

   
5.25767%

Accrued Interest Factor
    
0.003709383
      
0.004527438
  
Current Interest Due
  
$
361,993.55
    
$
93,265.22
  
Interest Shortfall from Prior Period Plus Accrued Interest
    
-
      
-
  
Total Interest Due
  
$
361,993.55
    
$
93,265.22
  
Interest Paid
  
$
361,993.55
    
$
93,265.22
  
Interest Shortfall
    
-
      
-
  
Principal Paid
  
$
773,008.87
      
-
  
Ending Principal Balance
  
$
96,815,618.47
    
$
20,600,000.00
  
Paydown Factor
    
0.001064751
      
0.000000000
  
Ending Balance Factor
    
0.133354846
      
1.000000000
  

* Pay rates for Current Distribution.  For the interest rates applicable to the next distribution date, please see https://images.navient.com/investors/data/abrate.txt.

Page 8 of 9
Trust 2013-4 Monthly Servicing Report: Collection Period 08/01/2026 - 08/31/2026, Distribution Date 09/25/2026
VIII.
2013-4 Reconciliations

A
Principal Distribution Reconciliation
      

Notes Outstanding Principal Balance  
$
118,188,627.34
  

Adjusted Pool Balance  
$
118,601,634.82
  

Overcollateralization Amount  
$
1,186,016.35
  

Principal Distribution Amount
 
$
773,008.87
  

Principal Distribution Amount Paid  
$
773,008.87
  
           
B
Reserve Account Reconciliation
        

Beginning Period Balance  
$
748,897.00
  

Reserve Funds Utilized    
0.00
  

Reserve Funds Reinstated    
0.00
  

Balance Available  
$
748,897.00
  

Required Reserve Acct Balance
 
$
748,897.00
  

Release to Collection Account  

-
  

Ending Reserve Account Balance  
$
748,897.00
  
           
C
Floor Income Rebate Account
        

Beginning Period Balance  
$
272,095.19
  

Deposits for the Period  
$
87,107.72
  

Release to Collection Account   $
(272,095.19)


Ending Balance  
$
87,107.72
  
           
D
Supplemental Purchase Account
        

Beginning Period Balance    
-
  

Supplemental Loan Purchases
   
-
  

Transfers to Collection Account    
-
  

Ending Balance    
-
  


Page 9 of 9
Trust 2013-4 Monthly Servicing Report: Collection Period 08/01/2026 - 08/31/2026, Distribution Date 09/25/2026