Roth conversion December 31 deadline: what still has to clear with the custodian
See the lane if MAGI is the worry. Filing status and MAGI. Two questions. No account. Nothing uploaded. Not a bill, and not a conversion amount.
Run the free checkWho this page is for
This page is for households considering a same-year Roth conversion before year-end. The job here is a list: which accounts, who to call, and what to ask. It is not a dollar picker.
Whether a conversion that lands in a tax year can meet a Medicare line two years later stays on Roth conversions and the Medicare premium. This page is only the year-end processing clock.
What to write down, and what to ask
Two calls. The custodian that holds the account, for the processing date and whether a conversion from that account can count in this tax year. A CPA, for how a conversion that clears this year is reported, and whether it changes estimated taxes or withholding. Neither call on this page includes a conversion amount.
| Write down | Question for the firm or a CPA |
|---|---|
| Each pre-tax account (traditional IRA or similar), and the firm that holds it | Does this firm allow a conversion from this account for the current tax year? |
| The date a request would be submitted | What is the last day a request can arrive so the conversion can count in this tax year? |
| Whether the conversion must clear by December 31 | Does the firm require the conversion to settle, clear, or be completed by December 31? |
| How the conversion will be reported | Which year-end tax form will show it, and which tax year will that form assign it to? |
| Estimated taxes and withholding | If the conversion counts this year, does a CPA see a change to estimated tax payments? If the firm withholds tax, does that reduce the amount that moves to the Roth, and how is the withheld amount reported? |
| A required distribution on the same account, if one applies | Does a required amount have to leave the account before any conversion of the remaining balance? |
The public date and the firm's date are not the same thing. December 31 is the calendar date for a conversion meant to count in that tax year. A traditional IRA contribution can still be made up to the filing deadline for the prior year. A conversion does not get that extra window. The federal description is in IRS Publication 590-A. The firm's own last day can be earlier, because the firm needs time to process the move. This page does not name one firm's cutoff.
A required minimum distribution is generally not itself converted. If both clocks are open, the questions are separate. The December 31 list for required distributions is on the RMD deadline checklist. This page does not calculate either amount. Withholding and estimated taxes stay as questions for the firm and a CPA. This page does not calculate a payment, a bracket, or a penalty.
A conversion that counts this year is this year's income
A conversion that counts in 2026 is 2026 income. MAGI on this site is Form 1040 line 11 plus line 2a. That 2026 return is the one generally used for the 2028 Medicare premium. It does not reset the 2026 premium, which is already tied to the 2024 return. This page does not calculate tax brackets or IRMAA.
The year pairs are on which return year sets Medicare IRMAA. What the lines include is on what is MAGI for Medicare. The free check is a lane, UNDER or OVER, on the return Medicare is already using. It is not a conversion worksheet, and it does not assign a premium for a later year.
Year-end briefing for a CPA. The Roth Conversion CPA Briefing Kit ($39) is an educational packet for that December 31 custodian clock. It does not say whether to convert. It does not pick a conversion dollar amount. It does not calculate tax brackets or IRMAA. It is not the $99/year household board. If the open question is MAGI against the Medicare line, the free check above is the lane check.
Roth Conversion CPA Briefing Kit ($39)Related reading
Common questions
When is the Roth conversion deadline for a tax year?
For a conversion that is meant to count in the current tax year, December 31 of that calendar year is the public date. A conversion does not stay open until the April filing deadline the way a traditional IRA contribution can. The custodian's last day to accept a request can be earlier, because the firm needs time to process the conversion before the calendar date. Ask the firm that holds the account for that request date. This page does not name one firm's cutoff.
Can a Roth conversion requested on December 31 still miss the tax year?
Yes. A request that reaches the firm on December 31 can still miss the year if the firm needs time to move the money. Ask the firm whether the conversion must settle, clear, or be completed by December 31, and what date a request must arrive. This page does not name one firm's cutoff.
Does this page say whether to convert, or how much?
No. This page does not say whether to convert. It does not pick a conversion dollar amount. It does not calculate tax brackets or IRMAA. Confirm the date, the accounts, and the tax treatment with the custodian and a CPA. The premium question two years later is on Roth conversions and the Medicare premium.
This page does not say whether to convert. It does not pick a conversion dollar amount. It does not calculate tax brackets or IRMAA. Confirm the request date, whether the conversion must clear by December 31, and the tax treatment with the custodian and a CPA. Educational only. Not tax, legal, Medicare, or investment advice. MAGI here is Form 1040 line 11 plus line 2a, as described in the IRS Form 1040 instructions.