Roth Conversions in Retirement: A Tax-Smart Strategy for Long-Term Savings

The Tax Arbitrage Window

Most people's financial lives follow a predictable tax pattern. During your working years, you earn the most and pay the highest tax rates. In retirement, your income typically drops — at least temporarily.

That temporary dip is a golden opportunity.

Between the day you retire and the day your Required Minimum Distributions (RMDs) begin at age 73, many retirees find themselves in a lower tax bracket than they've been in for decades. Maybe you're living on savings, taking modest Social Security, and your taxable income is unusually low.

This is the Roth conversion window — the period where you can strategically move money from your traditional IRA (pre-tax, taxable on withdrawal) to a Roth IRA (after-tax, tax-free on withdrawal) at a lower tax rate than you'd otherwise pay.

The concept is simple: pay 22% tax now to avoid paying 32% tax later. Multiply that savings across hundreds of thousands of dollars, and the impact is enormous.

How Roth Conversions Work

The mechanics are straightforward:

1. You tell your IRA custodian to convert a specific dollar amount from your traditional IRA to your Roth IRA
2. The converted amount is added to your taxable income for that year
3. You pay ordinary income tax on the conversion (ideally from non-IRA funds)
4. From that point forward, the converted money grows tax-free in the Roth
5. Qualified withdrawals from the Roth are completely tax-free

There's no limit on how much you can convert in a single year. There's no income restriction. There's no age limit. And since 2018, there's no option to reverse a conversion — so plan carefully.

When Roth Conversions Make Sense

Roth conversions aren't always a good idea. They're a calculated bet that your future tax rate will be higher than your current rate. Here's when the math typically works:

You're in a temporarily low tax bracket. The years between retirement and RMDs are often the sweet spot. If you're in the 12% or 22% bracket now but expect RMDs to push you into the 24% or 32% bracket, converting makes strong financial sense.

You expect tax rates to increase. The 2017 Tax Cuts and Jobs Act provisions are currently set to expire after 2025, which could push many brackets higher. If you believe future rates will be higher than today's, converting now locks in the lower rate.

You want to leave a tax-free inheritance. Under the SECURE Act, most non-spouse beneficiaries must empty an inherited IRA within 10 years. If they inherit a traditional IRA, those distributions are taxable. If they inherit a Roth IRA, the distributions are tax-free. Converting now is essentially pre-paying your heirs' tax bill at your (presumably lower) rate.

Your RMDs will be larger than you need. If your traditional IRA is large enough that future RMDs will exceed your spending needs and push you into higher brackets, reducing the IRA balance through conversions now can lower those future forced distributions.

You don't need the money in the near term. The converted money should stay in the Roth for at least 5 years to avoid penalties on earnings. The longer it compounds tax-free, the more valuable the conversion becomes.

When Conversions Don't Make Sense

You're already in a high tax bracket. If your current rate is 32% or higher and you don't expect it to change, paying tax now doesn't create an advantage.

You'll need the money within 5 years. Converted principal can be withdrawn anytime, but earnings on converted amounts are subject to the 5-year rule. Converting and then withdrawing defeats the purpose.

The conversion pushes you into IRMAA territory. Medicare's Income-Related Monthly Adjustment Amounts add surcharges to your Part B and Part D premiums when your modified adjusted gross income exceeds certain thresholds. A conversion that triggers IRMAA may still be worthwhile — but the added cost needs to be factored in.

You expect to be in a much lower bracket in retirement. If you're a high earner now and expect to live very modestly in retirement, the math might not favor conversion.

The Tax Bracket Filling Strategy

The most common and effective approach is filling up your current tax bracket with conversions — converting just enough each year to reach the top of your bracket without spilling into the next one.

Here's an example for a married couple filing jointly in 2026:

• Their taxable income from Social Security and a small pension is $60,000
• The 22% bracket extends to approximately $96,950 (2025 brackets, adjusted for inflation)
• They can convert roughly $37,000 and stay entirely within the 22% bracket
• Tax cost: approximately $8,140

If they do this every year for 8 years between retirement and RMDs, they convert roughly $296,000 from traditional to Roth — all at 22%. Without the conversions, those funds might be distributed at 24% or higher once RMDs force larger withdrawals.

Savings: approximately $6,000-$15,000+ in lifetime taxes, depending on growth and future rates.

The exact numbers depend on your situation, but the principle is universal: converting in the "gap years" between retirement and RMDs is one of the highest-impact financial planning strategies available.

How Annuities Enable Bigger Conversions

Here's where annuities and Roth conversions work together beautifully.

The challenge with Roth conversions is that you need to pay living expenses while simultaneously paying conversion taxes — without dipping into the funds you're converting. If you don't have enough income to cover both, you're limited in how much you can convert.

Annuity income solves this problem.

If your essential monthly expenses are $5,000 and Social Security covers $3,000, you have a $2,000/month gap. Without other income, you'd need to withdraw from your IRA to cover living expenses — reducing the amount available for conversion and potentially pushing you into a higher bracket.

But if you purchased a SPIA or activated an income rider that pays $2,000/month, your expenses are fully covered by guaranteed income. Now every dollar in your traditional IRA is available for strategic conversion. You can convert up to the top of your bracket each year, pay the tax from a savings account, and steadily shift your retirement wealth from taxable to tax-free.

The annuity doesn't just provide retirement income — it provides the financial runway for a multi-year Roth conversion strategy.

IRMAA: The Medicare Premium Trap

One of the most overlooked costs of Roth conversions is the impact on Medicare premiums.

Medicare Part B and Part D use Income-Related Monthly Adjustment Amounts (IRMAA) based on your Modified Adjusted Gross Income (MAGI) from two years prior. For 2026, the IRMAA thresholds for a married couple filing jointly are approximately:

A large Roth conversion that pushes your MAGI from $200,000 to $260,000 would cost an extra $148/month ($1,776/year) in Medicare premiums for the household — and that surcharge hits two years after the conversion year.

This doesn't mean you should avoid conversions. It means you should model the IRMAA impact alongside the tax savings. Often, the long-term Roth benefit far outweighs a one-time IRMAA bump. But $1,776 is real money, and it should be part of the calculation.

Roth Conversions and RMDs

Once your RMDs begin at age 73, Roth conversions become more complex — but not impossible.

You cannot convert your RMD itself. The IRS requires that your RMD for the year be satisfied first. You must take the RMD (and pay tax on it), and then you can convert additional funds from the traditional IRA to the Roth.

This means that after age 73, your taxable income already includes the RMD, which may push you into a higher bracket and reduce the conversion benefit. This is precisely why the years before 73 are so valuable for conversions.

That said, if your RMD only partially fills your bracket, you can still convert additional funds up to the bracket ceiling. Every dollar converted is a dollar that won't generate future RMDs — so even modest post-73 conversions have value.

The Multi-Year Conversion Plan

The most effective Roth conversion strategy is a multi-year plan, not a one-time event. Here's a framework:

Years 1-2 of retirement: Understand your new income baseline. Observe your tax bracket without conversions. File your first retirement tax return.

Years 3-8 (before RMDs): Execute annual conversions, filling your tax bracket each year. Adjust based on market conditions (converting when the market is down means more shares for fewer tax dollars), life changes, and IRMAA planning.

Age 73+: Reassess. Take RMDs, convert additional amounts if bracket space allows, and shift focus to enjoying the tax-free Roth distributions.

Throughout this period, your annuity income provides the stable foundation that makes the strategy possible. You're not worried about market volatility affecting your living expenses, and you're not forced to sell investments at inopportune times.

The Bottom Line

Roth conversions in retirement aren't glamorous. They don't involve complex products or exotic strategies. They're simply the disciplined, annual practice of moving money from a taxable bucket to a tax-free bucket while the tax cost is as low as possible.

But over a 10-year conversion window, the impact can be transformative. Tens of thousands — sometimes hundreds of thousands — in lifetime tax savings. A tax-free inheritance for your heirs. Reduced RMDs. Freedom from worrying about future tax rate changes.

The key ingredients: a clear understanding of your tax brackets, a reliable income source (like an annuity) to cover expenses during conversion years, and the discipline to execute the strategy consistently.