Roth Conversions After 73: Can You Still Convert While Taking RMDs?

Short answer: yes. You can do Roth conversions at any age — 73, 80, even 90. There is no age limit on conversions. But once required minimum distributions begin, two rules change the math significantly: you must satisfy your RMD before converting, and the RMD income itself eats into your bracket capacity before a single conversion dollar gets added.

Why RMDs can't be converted (the legal basis)

Under IRC §408(d)(3)(E), any amount that is required to be distributed (i.e., an RMD) is not an eligible rollover distribution.¹ Because a Roth conversion is structurally a distribution followed by a contribution to a Roth IRA, the conversion path requires that the amount being moved is "eligible to be rolled over." RMDs fail that test by statute.

The practical implication: the first dollars distributed from your traditional IRA in any year are automatically treated as satisfying your RMD. You cannot recharacterize those dollars as a conversion after the fact. Take the RMD first, then convert whatever additional amount you choose from the remaining balance.

For 401(k)s, the same rule applies at the plan level: the first distribution from a 401(k) plan in an RMD year goes toward satisfying that plan's RMD before any remaining balance is eligible for rollover to a Roth IRA.²

The income stacking problem

Before RMDs, a retiree with pension income of $50,000 MFJ had roughly $129,000 of bracket capacity at 22% (after deductions) before a conversion starts costing more. Once RMDs begin, that same retiree might have a $75,000 RMD on top of $50,000 in other income — leaving only $54,000 of 22% capacity for conversions, not $129,000.

The math with a concrete example for a married couple both age 75 in 2026:

In this scenario, a conversion is still feasible — but the IRMAA constraint often binds sooner. Their MAGI is already $149,311. Adding a $68,689 conversion would push MAGI to $218,000 — exactly at the MFJ IRMAA Tier 1 boundary.⁴ Crossing that line adds roughly $2,000/year per couple in Medicare Part B surcharges, with the two-year lookback meaning 2026 conversion income drives 2028 Medicare premiums.

Bracket headroom estimator (post-RMD)

Use this to estimate how much you can convert in 2026 after accounting for your RMD and other income. It applies the same bracket-filling logic as the Roth Conversion Sizing Calculator — but starts from your post-RMD income position.

When Roth conversions after 73 still make sense

The pre-73 window is more efficient for most people — more bracket capacity, no RMD stacking, more time for Roth assets to compound. But post-73 conversions aren't pointless. Five scenarios where they still deliver value:

1. Your heirs are in higher brackets than you. If your children are in the 32–37% bracket and you're paying 22–24% on conversions today, the arbitrage runs in the right direction. The converted dollars leave the Roth to heirs completely income-tax-free. The inherited Roth IRA still follows the 10-year rule, but the distributions carry no income tax.⁵
2. You have an unusually low income year. One-time deductions (medical expenses that exceed the 7.5% floor, charitable bunching, a business loss) can open significant bracket capacity that wouldn't otherwise exist. A year with large deductions is a rare window to convert at a lower effective rate than usual.
3. You have a surviving-spouse scenario to plan around. When one spouse dies, the survivor typically falls to single-filer rates. The single brackets are roughly half as wide as MFJ — meaning the same income suddenly crosses bracket boundaries sooner. Conversions while both spouses are alive and in MFJ status can dramatically reduce the tax cost of future single-filer RMDs.
4. You expect bracket thresholds to shrink. If you believe current rates will rise or brackets will narrow due to future legislation, locking in today's rates via conversion has option value regardless of RMD stage.
5. Estate simplification. Roth IRAs have no lifetime RMDs, grow tax-free, and pass to heirs with no income tax on the account itself. For a retiree who doesn't need IRA distributions for spending, a Roth conversion is also a way to convert a future RMD obligation into an inheritance asset that doesn't generate taxable income for anyone.

The IRMAA interaction: planning for 2028 Medicare premiums

IRMAA uses a two-year lookback — your 2026 MAGI drives your 2028 Medicare premiums. Roth conversions in 2026 become part of 2026 MAGI. Combined with a $75,000–$100,000 RMD, conversion income can easily push a retiree through the first IRMAA cliff.

For 2026, the Tier 1 IRMAA threshold is $109,000 MAGI for single filers and $218,000 for MFJ (based on 2024 MAGI for the 2026 premium year).⁴ For planning 2028 Medicare, use the 2026 thresholds as a reasonable approximation — actual 2028 IRMAA thresholds will be published in late 2027.

The typical post-73 conversion strategy: size the conversion to land just below the next IRMAA cliff, not just below the next bracket ceiling. In many cases, the IRMAA cliff is the binding constraint. Use the calculator above to find your IRMAA-capped room alongside your bracket headroom.

Two complementary moves reduce the IRMAA exposure of a conversion in the same year:

• QCDs first. Route charitable giving from the IRA as a Qualified Charitable Distribution (up to $111,000 in 2026).⁶ QCDs reduce MAGI dollar-for-dollar — creating headroom that a conversion can then use. A retiree with a $90K RMD who does $20K QCD brings their MAGI from the IRA down to $70K, freeing $20K of IRMAA headroom for conversion.
• Sequence the QCD to come before the conversion. QCDs count toward the RMD but are excluded from income. Take the QCD first (within your RMD amount), then take the remaining RMD as ordinary income, then convert any additional amount. This maximizes income exclusions before conversion income begins to stack.

Common mistakes

Mistake 1: Converting the RMD amount first, income-reporting separately. Some retirees assume they can take the distribution and immediately roll it to a Roth, then report the RMD separately. The IRS tracks distributions — the first dollar out satisfies the RMD. Taking the distribution and placing it in a Roth IRA is an invalid rollover of an RMD; the IRS will treat it as a prohibited contribution. The fix: take the RMD in cash first, then separately instruct the custodian to convert additional IRA balance to Roth.

Mistake 2: Forgetting that conversion income is not eligible for the QCD exclusion. QCDs reduce income; conversions add income. These are separate transactions. You cannot offset a Roth conversion with a QCD in the same year — the QCD excludes only the IRA distribution that flows to charity, not other income. The value of QCDs is reducing the pre-conversion MAGI to create headroom.

Mistake 3: Ignoring the 5-year clock for first-time Roth IRA owners. At 73, the early-withdrawal penalty (10%) is not an issue — you're past 59½. But if you've never had a Roth IRA before, earnings in the newly opened account are not "qualified" (tax-free) until five years have passed from the first Roth contribution or conversion. Principal (converted amounts) is always accessible without tax or penalty, but earnings incur ordinary income tax if withdrawn before the 5-year window closes. For most retirees using Roth as an estate vehicle, this is irrelevant — but it matters if you plan to draw from earnings before year 5.⁷

Pre-73 vs. post-73 conversions: what changes

How to structure a post-73 conversion year

1. Calculate your RMD. Use the RMD Calculator to get the required amount from each account. Confirm with your custodian.
2. Route any charitable giving as QCDs. If you give to charity, take that amount first as a QCD (reduces MAGI, counts toward RMD). Use the QCD Calculator to model the income savings.
3. Take the remaining RMD in cash. This satisfies the RMD obligation. Do not place it in a Roth — it is not eligible.
4. Estimate your MAGI and bracket position. RMD + other income sets your pre-conversion baseline. Check your IRMAA proximity — the Tier 1 cliff is $109,000 (single) / $218,000 (MFJ).
5. Size the conversion. Using the estimator above (or the Roth Conversion Sizing Calculator), find the amount that fills bracket space without crossing IRMAA. The IRMAA constraint almost always binds before the bracket ceiling for retirees with large RMDs.
6. Execute the conversion with your custodian. A direct custodian-to-custodian trustee transfer from traditional IRA to Roth IRA is the cleanest form — no 60-day rollover window to manage.
7. Adjust withholding. Roth conversions are ordinary income. If your regular withholding doesn't cover the additional tax, adjust estimated tax payments. See the RMD Tax Withholding guide for the year-end lump-sum strategy.