Situation guide
Roth conversions for couples with an age gap: whose IRA to convert first
By Secure Retirement PlannerUpdated
If there's a big age gap in your marriage, the older spouse's IRA is often the one to convert first in 2026. The older of you usually reaches required minimum distributions (RMDs) and Medicare first. On average, the older spouse also dies first. That can leave the younger one paying single-filer tax rates for many years. Converting while you can still file jointly lets you use the wider joint brackets.
There is one helpful rule too. Is your spouse more than 10 years younger and the only beneficiary of your IRA? Then your RMDs use a longer life expectancy, so they are smaller. This page covers that rule, your Medicare timing and the widow's penalty risk, with a 2026 example.
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The short version
- If your spouse is more than 10 years younger and your sole beneficiary, you use the Joint Life and Last Survivor table. That lowers your RMDs.
- The younger of you may file as single for decades. Converting while you file jointly uses brackets twice as wide.
- Medicare surcharges for the older spouse use your joint income, including the younger spouse's paycheck.
- If only one of you is 65 or older, you get only one $6,000 senior deduction. It shrinks by 6 cents per dollar over $150,000.
- Converting the older spouse's IRA first cuts the RMDs that start soonest. It also cuts the balance the survivor will inherit.
How do RMDs work when my spouse is more than 10 years younger?
Most IRA owners figure RMDs with the Uniform Lifetime Table. Your spouse may be more than 10 years younger and the sole beneficiary of your IRA. If so, you use the Joint Life and Last Survivor Expectancy table (Table II in IRS Publication 590-B). It uses both your ages, so the divisor is larger and your RMD smaller.
The rule applies account by account. If you name your children as co-beneficiaries, that IRA goes back to the Uniform table. You can check your own numbers with RMD calculator.
| Owner's age / spouse's age | Joint Life divisor | RMD (Joint Life) | Uniform table divisor | RMD (Uniform table) |
|---|---|---|---|---|
| 74 / 62 | 27.0 | $3,704 | 25.5 | $3,922 |
| 78 / 66 | 23.4 | $4,274 | 22.0 | $4,545 |
| 80 / 68 | 21.6 | $4,630 | 20.2 | $4,950 |
Smaller RMDs, same tax bill later
The Joint Life table delays your withdrawals. It doesn't make them tax-free. The money left in your IRA is still taxed when it comes out, often by the younger spouse at single rates.
Why does an age gap raise the widow's penalty risk?
The widow's penalty is the higher tax you pay as a survivor once you switch from joint to single filing. Your single brackets and standard deduction are about half the joint ones. Your income usually falls much less.
With a large age gap, the younger of you may file as single for 15 or 20 years. They inherit your IRAs, so RMDs keep coming. They also keep the larger Social Security check. Money you convert while you still file jointly won't be taxed at single rates later. If you worry about your spouse's tax bill after you're gone, this is the part to plan for. Widows and widowers covers the year-of-death rules.
How does Medicare IRMAA work when only one spouse is on Medicare?
IRMAA, Medicare's income-related surcharge, uses the income on your joint tax return from two years earlier. That includes your younger spouse's wages, even if they aren't on Medicare yet. For 2026 premiums, the first surcharge starts above $218,000 of your joint income.
Until your younger spouse turns 65, only you, the older spouse, pay the surcharge. Crossing the first line costs about $1,148 a year for one person at 2026 rates. That is half what a couple both on Medicare would pay. Your conversions before the younger spouse turns 63 never count toward their own premiums. See Roth conversions and IRMAA for the tiers.
Should we convert the older spouse's IRA first?
Often, yes. On a joint return, your tax on a conversion is the same whichever spouse's IRA it comes from. What differs is what happens next.
If you're the older spouse, your IRA faces RMDs first, and those RMDs add to your taxable income every year. Converting it shrinks your RMDs. It is also the account the younger spouse is likely to inherit and draw down as a single filer. A spouse who inherits a Roth can treat it as their own, with no RMDs during their life.
Keep two cautions in mind. If you're the older spouse and already taking RMDs, your RMD for the year must come out before you convert from that IRA. And your younger spouse's own account may still be worth converting in years when you have spare room. Their RMDs just come much later.
- Convert the account whose RMDs start first.
- Take the year's RMD before converting from that IRA.
- Keep the younger spouse as sole beneficiary to keep the Joint Life table on what remains.
- Check the senior deduction: only the spouse who is 65 or older gets it.
Example: a 74-year-old husband and 62-year-old wife
Ron is 74 and Maria is 62. Ron was born in 1952 and started RMDs at 73. His IRA was worth $900,000 at the end of 2025. Maria is his sole beneficiary, so his 2026 RMD uses the Joint Life divisor of 27.0: $33,333. With the Uniform table it would be $35,294. Ron gets $40,000 a year of Social Security. Maria earns $70,000 and plans to work until 65.
Their 2026 income before converting is $137,333, including $34,000 of taxable Social Security. Their deductions are $39,850. That is the $32,200 standard deduction, $1,650 for Ron being over 65, and Ron's $6,000 senior deduction. Maria doesn't get a senior deduction yet. Taxable income is $97,483, so only about $3,300 of the 12% bracket is left.
Above $150,000 of income, Ron's senior deduction shrinks by 6 cents per dollar. So conversion dollars there cost about 23.3% instead of 22%. A conversion of up to about $80,000 keeps their income under $218,000, the first Medicare surcharge line. Ron's 2028 premium would not go up, and Maria won't be on Medicare until 2029.
If your marriage looks like Ron and Maria's, think about converting the older spouse's IRA now, at joint rates. That can mean less tax for whichever of you is left later. Just keep your eye on the Medicare line.
| 2026 conversion | Income (MAGI) after | Added federal tax | Average rate on the conversion |
|---|---|---|---|
| $3,000 | $140,333 | about $360 | 12.0% |
| $50,000 | $187,333 | about $11,161 | 22.3% |
| $80,000 | $217,333 | about $18,157 | 22.7% |
Hypothetical example using 2026 federal brackets, standard deduction and senior deduction (IRS Rev. Proc. 2025-32 and the One Big Beautiful Bill Act), RMD divisors from IRS Publication 590-B and the IRS Publication 915 method for taxing Social Security. Assumes no other income and no state tax. Uses 2026 IRMAA tiers as a stand-in for 2028, which weren't published as of Nov 9, 2026. Your numbers will differ.
Common questions
When can I use the Joint Life and Last Survivor table?
When your spouse is more than 10 years younger than you and is the sole beneficiary of that IRA. Otherwise, you use the Uniform Lifetime Table.
Does my younger spouse's income count toward my IRMAA?
Yes, if you file jointly. Medicare uses the joint return's income from two years earlier, including your spouse's wages and any conversions from either of your accounts.
Whose IRA should we convert first?
Often the older spouse's. Its RMDs start first, and the younger spouse is likely to inherit it and pay single rates later. Your tax that year is the same either way.
Do we both get the $6,000 senior deduction?
Only a spouse who is 65 or older gets it. Each spouse's $6,000 shrinks by 6% of your joint income over $150,000.
Does converting reduce the benefit of the Joint Life table?
It lowers the balance your RMDs are figured on, so your RMDs get smaller still. The table only changes the divisor, not the tax on what you convert.
Can my younger spouse convert my IRA after I die?
Yes. Your surviving spouse can treat the IRA as their own or roll it over. Then they can convert any part, after taking any RMD due for the year of death.
Sources
Facts on this page were last checked on November 9, 2026.
- IRS Publication 590-B, Distributions from IRAs · Sole beneficiary spouse more than 10 years younger, Table II and Table III divisors, spouse beneficiary options. Read Nov 9, 2026.
- CMS: 2026 Medicare Parts A & B premiums and deductibles · 2026 IRMAA tiers and two-year lookback. Read Nov 9, 2026.
- IRS Rev. Proc. 2025-32 (2026 inflation adjustments) · 2026 brackets, standard deduction and extra deduction for 65 or older. Read Nov 9, 2026.
- IRS Schedule 1-A (Form 1040), Additional Deductions, Part V · $6,000 per person 65 or older, reduced by 6% of MAGI over $150,000 joint. Read Nov 9, 2026.
- IRS Publication 915, Social Security and Equivalent Railroad Retirement Benefits · Method for the taxable part of Social Security. Read Nov 9, 2026.
Who wrote this
This guide was written and fact-checked by the Secure Retirement Planner editorial team using IRS, CMS and Social Security sources listed above. We update guides when the law or yearly limits change. How we research.