There is no age limit on Roth conversions. Someone in their 70s, 80s, or 90s can move money from a traditional IRA, SEP IRA, SIMPLE IRA, or an employer plan like a 401(k) into a Roth IRA, and there is no income ceiling either. The complication for older account holders is the required minimum distribution rule, which forces you to pull out a mandatory amount before you convert whatever is left. That interaction trips up more retirees than any other part of the process.
Why Age Doesn’t Block a Conversion
Federal law has never set an upper age limit on Roth conversions. Before 2010, a different barrier applied: you could not convert if your modified adjusted gross income exceeded $100,000. The Tax Increase Prevention and Reconciliation Act of 2005 eliminated that income restriction starting in 2010, opening conversions to everyone regardless of earnings.1United States Congress. Tax Increase Prevention and Reconciliation Act of 2005 Today, anyone with assets in a tax-deferred retirement account can convert any amount in any year.2Vanguard. IRA Roth Conversion
This is different from annual Roth IRA contributions, which still have both income limits and earned-income requirements. For 2026, you can contribute up to $7,500 per year to a Roth IRA ($8,600 if you are 50 or older), but only if your income falls below certain thresholds.3Internal Revenue Service. Retirement Topics – IRA Contribution Limits Conversions sidestep both of those limits because you are moving existing retirement money, not making a new contribution.
The government’s willingness to keep conversions open makes practical sense. Every dollar you convert from a pre-tax account becomes taxable income in the year of conversion, generating immediate revenue for the Treasury. You get tax-free growth going forward.
RMDs Must Come Out First
Once you reach your RMD age, you have to withdraw a minimum amount from traditional IRAs and most employer plans each year. Under the SECURE 2.0 Act, that age is 73 if you were born between 1951 and 1959, and 75 if you were born in 1960 or later. You can still convert after that age, but the RMD for the year has to come out before any conversion.
The IRS treats the first dollars leaving a traditional IRA in any RMD year as satisfying the required distribution.4Internal Revenue Service. Roth Conversions – Retirement Planning for Life Events You cannot roll that mandatory amount into a Roth. If you try, the IRS treats it as an excess contribution to the Roth IRA, which triggers a 6% excise tax for every year the excess stays in the account.5Office of the Law Revision Counsel. 26 USC 4973 – Tax on Excess Contributions to Certain Tax-Favored Accounts and Annuities
The fix is straightforward. Calculate your RMD using the IRS Uniform Lifetime Table, withdraw that amount, and then convert whatever additional funds you want. Many retirees take the RMD early in the year so they can convert the remainder with time left to manage the tax hit across quarterly estimated payments.
How a Conversion Hits Your Medicare Premiums
A Roth conversion raises your adjusted gross income in the year you convert, and Medicare uses your income from two years earlier to set your premiums. A large conversion in 2024, for example, could push your 2026 Part B and Part D premiums into a higher bracket through the Income-Related Monthly Adjustment Amount, commonly called IRMAA.
For 2026, the standard Part B premium is $202.90 per month. IRMAA surcharges apply at the following thresholds based on modified adjusted gross income from your 2024 tax return:6Centers for Medicare & Medicaid Services. 2026 Medicare Parts A and B Premiums and Deductibles
- Over $109,000 single or $218,000 joint: $81.20 surcharge, bringing Part B to $284.10 per month
- Over $137,000 single or $274,000 joint: $202.90 surcharge, total $405.80
- Over $171,000 single or $342,000 joint: $324.60 surcharge, total $527.50
- Over $205,000 single or $410,000 joint: $446.30 surcharge, total $649.20
- $500,000 or more single or $750,000 or more joint: $487.00 surcharge, total $689.90
Part D prescription drug coverage carries its own IRMAA surcharges at the same income breakpoints, ranging from $14.50 to $91.00 per month.6Centers for Medicare & Medicaid Services. 2026 Medicare Parts A and B Premiums and Deductibles A single filer whose conversion pushes income above $205,000 could pay an extra $529.60 per month in combined Medicare surcharges for that premium year. Spreading a large conversion across multiple tax years is one of the most effective ways to stay below these thresholds.
Inherited IRAs Are a Different Story
If you inherited a traditional IRA from someone other than your spouse, you cannot convert it to a Roth IRA. The IRS does not allow non-spouse beneficiaries to shift inherited pre-tax assets into a Roth account. The inherited IRA follows its own distribution timeline, which under the SECURE Act is typically a full drawdown within 10 years of the original owner’s death.7Internal Revenue Service. Retirement Topics – Beneficiary
A surviving spouse has more flexibility. A spouse who inherits a traditional IRA can roll it into their own IRA, which then becomes their account in every sense. From there, they can convert to a Roth on their own schedule, subject to all the normal rules. This distinction is one reason many retirees convert their own accounts during life rather than leaving the decision to heirs who may not have the option.
The Pro-Rata Rule for Mixed IRA Money
If you hold multiple traditional IRAs, or a mix of deductible and nondeductible contributions across your accounts, the IRS does not let you cherry-pick which dollars to convert. Every conversion is taxed based on the ratio of pre-tax to after-tax money across all your traditional, SEP, and SIMPLE IRAs combined. This is the pro-rata rule.
An example makes it concrete. Say you have $95,000 in a rollover IRA (all pre-tax) and you contribute $5,000 to a new traditional IRA with after-tax dollars, intending to convert just that $5,000. Your total IRA balance is $100,000, and 95% of it has never been taxed. The IRS treats 95% of your $5,000 conversion as taxable income, not just the small slice you hoped would pass through tax-free.
The calculation runs through Part I of IRS Form 8606, where Line 6 asks for the total value of all your traditional IRAs as of December 31 of the conversion year, plus any outstanding rollovers.8Internal Revenue Service. Instructions for Form 8606 Employer plans like 401(k)s and 403(b)s are not counted. If your employer plan accepts incoming rollovers, you can move your pre-tax IRA balances into the 401(k) before converting, leaving only the after-tax IRA funds subject to the conversion.
Paying the Tax
A conversion creates income in the conversion year, taxed at your ordinary federal rate. For 2026, those rates range from 10% to 37%, with the top bracket starting at $640,600 for single filers and $768,700 for joint filers.9Internal Revenue Service. IRS Releases Tax Inflation Adjustments for Tax Year 2026 A conversion does not lock you into a single bracket; the converted amount stacks on top of your other income and is taxed progressively.
Three forms are involved in the reporting. Form 1099-R comes from your financial institution in January or February of the year after conversion, reporting the gross distribution and taxable amount.10Internal Revenue Service. Instructions for Forms 1099-R and 5498 Form 8606 goes with your tax return and calculates how much of the conversion is taxable, especially if you have any after-tax basis in your traditional IRAs; failing to file it when required carries a $50 penalty.11Internal Revenue Service. About Form 8606, Nondeductible IRAs On Form 1040, the total distribution goes on Line 4a and the taxable portion on Line 4b.12Internal Revenue Service. Instructions for Form 1040 and 1040-SR
A large conversion can produce a significant tax bill due by April 15 of the following year.13Internal Revenue Service. When to File If you don’t have enough withheld through other income sources, the IRS expects quarterly estimated payments to cover the gap. For 2026, estimated payments are due April 15, June 15, September 15, and January 15 of 2027.14Taxpayer Advocate Service. Making Estimated Payments If your total payments fall short, you’ll owe interest on the underpayment at the federal short-term rate plus three percentage points, which for the first quarter of 2026 is 7% annually.15Internal Revenue Service. Interest Rates Remain the Same for the First Quarter of 2026 You can generally avoid the penalty by paying at least 90% of the current year’s tax or 100% of the prior year’s tax, whichever is smaller.16Internal Revenue Service. Underpayment of Estimated Tax by Individuals Penalty
Don’t Forget State Income Tax
The federal bill is only part of the cost. Most states with an income tax treat Roth conversions as ordinary taxable income, the same way the IRS does. State top marginal rates range from zero in the nine states with no income tax (Alaska, Florida, Nevada, New Hampshire, South Dakota, Tennessee, Texas, Washington, and Wyoming) to over 13% in the highest-tax states. Timing a conversion during a year you live in a no-income-tax state, or before moving to a higher-tax one, can save a substantial amount. Check your state’s treatment before converting, because a handful of states have special rules for retirement income that could affect the calculation.