Guide · tax year 2026
Roth conversion deadline 2026: December 31
A Roth conversion counts for the tax year it is made. To count for 2026, it has to be made by December 31, 2026. There is no April window as there is for contributions, and a conversion cannot be undone.
What a 2026 conversion is measured against
The taxable part of what you convert by December 31, 2026 is added to your 2026income: all of it, unless the IRA holds after-tax contributions (basis on Form 8606). These are the 2026 lines it can push you over.
| Line | Measured on | Single | Married, joint |
|---|---|---|---|
| Top of the 12% bracket | taxable income at ordinary rates | $50,400 | $100,800 |
| Top of the 22% bracket | taxable income at ordinary rates | $105,700 | $211,400 |
| 0% long-term capital gains ceiling | taxable income | $49,450 | $98,900 |
| IRMAA tier 1 (estimate) | MAGI for IRMAA | $109,000 | $218,000 |
| ACA 400% FPL (household of 1 / 2) | MAGI for ACA | $62,600 | $84,600 |
IRMAA is set from 2026 income but charged on 2028 Medicare premiums; the 2028 tiers are not published yet, so the 2026 tiers stand in. The lines only rise with inflation, so these tiers are the lowest the later lines can be. The 2027 first line is already set at over $112,000 single, $224,000 joint. See IRMAA brackets 2027. The ACA line is for a household of one or two.
Roth conversion calculatorHow much you can convert in 2026 before the line you choose, and the federal tax it adds.
Open the calculatorWe’ll remind you to recheck before December 31
A conversion that fits today can cross a line once this year’s dividends and gains come in. We email you around November 20, when most of them are known, and again around December 15, before the 2026 deadline. Only your address is kept. One click stops them.
An example
A married couple, 66 and 64, with $38,400 of Social Security, $2,500 of interest, $9,000 of qualified dividends and $1,480,000 in a traditional IRA. This is the calculator’s starting example.
- Conversion by December 31, 2026fills the 12% bracket to $100,800 of taxable income at ordinary rates$105,510
- Federal tax it adds for 2026$12,950
- IRMAA tier 1 starts above$218,000
- −MAGI for IRMAA, which sets 2028 Medicare premiums$149,650
- =Room left under IRMAA tier 1$68,350
The same conversion on January 2, 2027 would fall into 2027 instead, against 2027’s brackets and 2029’s Medicare premiums.
Your IRA custodian decides how late in December it will process a conversion. Ask it for its cutoff.
If you are on a marketplace plan
A 2026 conversion also raises the income your 2026 premium tax credit is figured on. Above 400% of the poverty line the credit is lost in full, and for tax years after 2025 any advance credit is repaid in full. See Roth conversions and the ACA subsidy.
Questions
No. A conversion is income for the year you make it. Contributions for 2026 can still be made until the 2027 filing due date (not including extensions); conversions have no such window.
No. Conversions made in 2018 or later cannot be recharacterized back to a traditional IRA. Once it is done, it counts.
The amount you are required to take out for the year cannot be converted. The RMD calculator gives that amount, and the Roth conversion calculator withdraws this year’s RMD before it converts anything.
The converted amount is income on your 2026 return, so you may need to raise withholding or make an estimated tax payment for 2026.
The nondeductible contribution for 2026 can still be made until the 2027 filing due date, but the conversion step counts in the year it happens. A conversion in January 2027 is 2027 income, even when the contribution was for 2026.
Calculations, not tax, legal or investment advice.
Sources
The lines come from the same 2026 tables the Roth conversion calculator uses, and the example is that calculator’s result for its starting inputs.
Tables and sources
- IRS Publication 590-A (2025)Converting From Any Traditional IRA Into a Roth IRA; Recharacterizations; When Can Contributions Be Made? · 2025 · www.irs.gov
- Rev. Proc. 2025-32§4.01 Tables 1 and 3; §4.14(1) and (3); §4.03 · 2026 · www.irs.gov
- CMS fact sheet: 2026 Medicare Parts A & B Premiums and Deductibles (2025-11-14)Part B and Part D income-related monthly adjustment amounts; set from MAGI two tax years earlier · 2026 · www.cms.gov
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