Form 8621 News and Updates
Each item is checked against an official source before it is published. Last updated October 20, 2026.
Form 8621 and its instructions are revised (December 2025)
The IRS lists the current Form 8621 and its instructions as December 2025 revisions. The IRS page for the form shows no recent developments. New in the 2025 revision: a three-letter currency code space above Part V, line 15a. IRS Form 8621 page.
IRS underpayment interest rate is 7% for the fourth quarter of 2026
The IRS underpayment rate, used for the section 1291 interest charge, was 7% for the first quarter of 2026, 6% for the second and 7% for the third and fourth. Rates have been between 6% and 8% since the first quarter of 2023. IRS quarterly interest rates.
The Form 8621 instructions list a 37% top rate for 2018 through 2025
The extra tax on earlier-year amounts of an excess distribution uses the highest rate in effect for each earlier year. IRS Instructions for Form 8621.
Form 8621 lines on the 2025 Form 1040
Line 16b to Schedule 1, line 8z; line 16e to Form 1040, line 16 (box 3, code 1291TAX); line 16f to Schedule 2, line 17p. See the walkthrough.
What to watch next
- The IRS quarterly interest rate for the first quarter of 2027, announced before the quarter begins.
- Any change to the Form 8621 instructions for tax year 2026.
- New guidance on foreign funds, pension arrangements and the annual reporting rule. We update this site only after verifying the source.
News items are general information and are not legal or tax advice. Verify figures and deadlines on irs.gov and consult a qualified professional before acting.