Effective Dates: 03/10/2026 - Present Previous | Next

TN 8 (03-26)

DI 52170.015 Form SSA-3643 (Offset Worksheet – Triennial Redetermination)

A. Purpose of the Form SSA-3643

Use the SSA-3643 to compute increases in benefits resulting from a triennial redetermination. You may use the e2455+, a new tool for calculating amounts payable after workers’ compensation/public disability benefits (WC/PDB) offset, instead of the paper Form SSA-3643. The e2455+ can propagate offset rates into OREO, see DI 52165.020.

For more information, see Triennial Redetermination (Redet) of Average Current Earnings (ACE), DI 52150.080.

B. When to complete a Form SSA-3643

Complete a paper SSA-3643 only when you cannot use an Interactive Computation Facility (ICF) program or e2455+ due to systems limitations.

C. Form SSA-3643 exhibit

Click here for an example.

D. Disposition of the SSA-3643

If the SSA-3643 cannot be stored or recorded in the Modernized Claims System (MCS), Modernized SSI Claims System (MSSICS), or the ICF, fax the form into the Evidence Portal (EP) or the electronic disability (eDIB) folder (eView), as appropriate.

NOTE: If processing center (PC) action is required, the FO will also fax the form to the PC’s Paperless fax number.

E. Completing the SSA-3643

Enter the worker’s Social Security number.

1. Line A - Total benefits payable after offset in the month of redetermination but without considering the current redetermination

  • •

    Enter the amount payable to the family after offset in January of the year the redetermination is effective, (i.e., the amounts payable after offset for the month of the redetermination).

  • •

    Use those rates that are in effect before any increase, (e.g., recomputation) which may be applicable in the month of the redetermination.

  • •

    Consider only the number of beneficiaries entitled in that month.

  • •

    If a WC/PDB rate change occurs in the same month a redetermination (redet) is due, compute the WC/PDB rate first and then compute the redet. If a recomputation of the primary insurance amount (PIA) also applies in the same month after the WC/PDB rate change, compute the redet and then process the recomputation.

2. Line B - 100% original ACE (Before any redetermination)

Enter the 100 percent ACE. This is the original 100 percent ACE, not a previously redetermined or recomputed ACE.

3. Line C - Redetermination ratio (Effective date)

Show the year that the redetermination is effective.

Refer to the chart showing the year offset is first imposed, the effective year of the redetermination and the respective ratios in DI 52150.085.

Use 5-digit ratios beginning January 2004.

4. Line D - Redetermined 100 percent ACE

Enter the product of the 100 percent ACE (line B) multiplied by the appropriate ratio (line C). Reduce to the nearest dollar.

5. Line E - Redetermined 80 percent ACE

Enter 80 percent of the amount in line D.

6. Line F - Monthly WC/PDB

Enter the monthly amount of WC/PDB payable to the number holder in the effective month of the redetermination. Refer to instructions for converting to a monthly amount, DI 52150.035.

7. Line G - Total benefits payable after offset (E less F)

If the amount on this line does not exceed Line A, a redetermination does not apply.

If a redetermination does not apply:

  • •

    Circle total in line A.

  • •

    Scan or fax the form into the EP or the electronic claims folder (eView) as documentation and annotate a message to the MBR.

If a redetermination applies, continue to line H.

8. Line H - Protected auxiliary benefits

Enter the total amount of increases in auxiliary benefits not subject to offset because they are the result of a statutory increase, PIA recomputation, combining of maximums or a prior redetermination subsequent to the initial imposition of the offset. Include any AERO increase due in the redetermination month.

9. Line I - Balance payable (G less H)

Enter amount to be distributed to the family.

10. Line J - Workers’ PIA effective in the month of redetermination

Enter the number holder's PIA (unless reduced for age) that is in effect as of January of the year in which the triennial redetermination is effective. If the DIB PIA has been reduced for age, use the reduced MBA. Include any AERO increase due in the redetermination month but do not include any statutory increase that is effective after the effective month of the triennial redetermination (i.e., January).

11. Line K - Remainder payable to auxiliaries (I less J)

Enter balance amount payable.

12. Line L - Total payable to auxiliaries (Line H plus Line K)

Enter the total sum. If unequal auxiliary amounts are involved, refer to Part 2 (Offset Computation) of the SSA-2455 (Offset Worksheet-DIB).

13. Line M - Amount payable to each auxiliary

Divide the total payable to auxiliaries (line L) by the number of auxiliaries entitled in the effective month of the redetermination. This amount cannot exceed the unreduced monthly benefit amount. Follow the rounding rules in DI 52170.025.

14. Line N - Calculations

Show all calculations in the bottom sections of the form.

15. Signature and Date

Sign and date the form. Then, scan or fax into the EP or the electronic claims folder (eView).

16. ICF OREO

Complete an ICF OREO (Online Records Entry Operations) datasheet if possible.

To Link to this section - Use this URL:
http://policy.ssa.gov/poms.nsf/lnx/0452170015
DI 52170.015 - Form SSA-3643 (Offset Worksheet – Triennial Redetermination) - 03/10/2026
Batch run: 03/10/2026
Rev:03/10/2026