Updated October 19, 2026. Quick answer: Box 5 of Form RRB-1099-R is the vested dual benefit, or VDB, and box 6 is the supplemental annuity. Publication 575 describes each as a gross amount paid, less repayments, and says both are fully taxable. Repayments for earlier years are not taken out here; they appear in box 8.
What box 5 and box 6 report
After the pension amount in box 4, the form lists two more benefit types. Publication 575 describes them in short entries.
| Item | What Publication 575 says |
|---|---|
| Box 5, what it shows | “This is the gross amount of VDB payments paid in 2025, less any 2025 VDB payments you repaid in 2025.” |
| Box 5, taxable? | “It is fully taxable.” |
| Box 6, what it shows | “This is the gross amount of supplemental annuity benefits paid in 2025”, less repayments of those benefits, as the entry describes. |
| Earlier-year repayments | “VDB payments you repaid in 2025 for an earlier year or for an unknown year are shown in box 8.” |
Neither box has a cost to recover. Compare that with box 3, where the employee’s cost is shown. Those boxes are explained in Form RRB-1099-R boxes 3 and 4, and the whole form is mapped in the Form RRB-1099-R boxes guide.
Why these two are fully taxable
The publication gives the reason when it first introduces the form: “VDBs and supplemental annuity benefits are non-contributory pensions and are fully taxable.” That sentence is the basis for the short statements in the box 5 and box 6 entries, and it is why neither box leads into the partly taxable method that box 4 can.
The publication also describes where these benefits sit in the larger picture. The railroad benefits in the second category are “shown on Form RRB-1099-R”. For the tier structure behind them, see tier 1 and tier 2 railroad retirement taxation.
Gross amount less repayments
Both entries are the same in shape. Each starts from the gross amount paid and takes out repayments of that benefit. The supplemental annuity entry says: “It is fully taxable.” The same entry says repayments for earlier years “are shown in box 8.” So a repayment of an old overpayment does not shrink box 5 or box 6. It is reported separately, and Form RRB-1099-R boxes 7 to 12 explains box 8.
Payments for other years
The publication adds a note that applies to boxes 4 and 5: “The amounts shown in boxes 4 and 5 may represent payments for 2025 and/or other years after 1983.” That means a figure in these boxes is not necessarily all attributable to one year of entitlement. It is the amount paid in the year printed on the form. If you received a back payment, the box shows it in the year paid.
If you want a plain explanation of the benefit types before reading the boxes, start with how railroad retirement works or how railroad retirement is calculated.
Where the totals go
Box 7 adds boxes 4, 5 and 6 together, and the publication says what to do with it. The box 7 entry is covered in Form RRB-1099-R boxes 7 to 12, and the return line it names is described on Form 1040 lines 5a and 5b.
Edition and box numbers
This page reads the IRS’s description of Form RRB-1099-R in Publication 575 for 2025 returns (the box numbers and labels printed there). The form itself is issued by the Railroad Retirement Board, not the IRS, so the year and layout on the form you received govern; check the year printed on it.
Common mistakes
- Hunting for a tax-free part in box 5 or box 6. The publication says “VDBs and supplemental annuity benefits are non-contributory pensions and are fully taxable.”
- Subtracting an earlier-year repayment from box 5 yourself. The publication says such repayments “for an earlier year or for an unknown year are shown in box 8.”
- Assuming boxes 4 and 5 cover only 2025 payments. The publication notes “The amounts shown in boxes 4 and 5 may represent payments for 2025 and/or other years after 1983.”
Related: tier 1 and tier 2 railroad retirement taxation, how railroad retirement works, how railroad retirement is calculated, and Form 1040 lines 5a and 5b.
Sources
- Publication 575, Pension and Annuity Income (2025 returns): https://www.irs.gov/pub/irs-pdf/p575.pdf
- IRS: About Publication 575: https://www.irs.gov/forms-pubs/about-publication-575
Read from the IRS documents linked above on October 19, 2026. General information, not tax advice. Your own facts decide the outcome, and a preparer, the account provider or the IRS is the right place to confirm anything consequential.