We’re in our 50s and have $1.5 million in traditional 401(k)s. Is it too early to start Roth conversions?
Short answer: It’s not too early to consider them, but the “right” time depends on your current tax bracket versus the bracket you’re likely to face from required minimum distributions (RMDs), Social Security, and other income later. For many households, the best conversion window starts in the low-income years between retirement and the onset of RMDs and Medicare, but there are compelling reasons to begin in your 50s in some cases.
How to decide
– Core rule: Convert when your current marginal tax rate on the conversion is the same as or lower than the rate you expect on future withdrawals, RMDs, or for your heirs.
– Why this matters: Conversions trade a known tax bill today for reduced future RMDs, more tax flexibility in retirement, and potentially lower taxes for heirs. But if you convert in a high-tax year, you may pay more than necessary.
What your numbers might look like
– You have $1.5 million pre-tax. If it grows 5–6% annually for 15 years, it could be roughly $3.1–$3.6 million by age 65–70 (market-dependent).
– At age 73 (current RMD age for most born 1951–1959; age 75 for those born 1960+), the first RMD is about 1/26.5 of the balance, roughly 3.8%. On $3 million, that’s about $114,000 the first year, rising over time. Add two Social Security benefits, and you could land squarely in mid-to-upper tax brackets in retirement even without earned income.
– That future tax profile often justifies converting some dollars earlier, especially in years you can “fill up” a lower bracket.
When starting in your 50s can make sense
– You’re already in or can keep conversions within the 22–24% federal bracket (through 2025 under current law), and you expect to be in the 28–32%+ range later from RMDs and Social Security.
– You plan to retire early and want to smooth taxes by spreading conversions over more years instead of cramming them into the 60s.
– You want to hedge against the scheduled 2026 tax law sunset that would raise today’s 22% and 24% brackets to 25% and 28% (with other changes that generally increase many retirees’ effective tax rates).
– Estate planning matters: most non-spouse heirs must empty inherited IRAs within 10 years. Inheriting Roth IRAs is still subject to that window, but withdrawals are income tax–free to them.
When waiting can be smarter
– You’re in your peak earning years and already in a high bracket (32–37% federal). If you’ll retire soon into a much lower bracket, delaying conversions to those lower-income years often wins.
– You’ll rely on ACA health insurance before age 65. Conversions raise your modified AGI and can sharply reduce premium subsidies.
– You plan to move from a higher- to lower-tax state in a few years. Converting after the move can cut or eliminate state income tax on the conversion.
How to execute efficiently
– Fill the bracket: Each calendar year, target a conversion amount that brings your taxable income to the top of a chosen bracket without spilling into the next. Account for bonuses, capital gains, and dividends.
– Coordinate with capital gains: Roth conversions increase your AGI and can cause more of your investment income to be taxed at higher rates or trigger the 3.8% Net Investment Income Tax on gains and dividends.
– Mind Medicare and ACA:
– Medicare IRMAA surcharges at 65 are based on MAGI from two years earlier. Big conversions at 63 can raise Part B/D premiums at 65. If you’re going big, consider finishing by age 62 or accept the surcharge as part of the cost/benefit.
– Before 65, conversions can reduce or eliminate ACA premium tax credits. Model this carefully if you retire before Medicare.
– Pay taxes from taxable savings: Don’t withhold taxes from the conversion itself if you can avoid it—using outside cash keeps more money in tax-advantaged accounts compounding tax-free.
– Consider market declines: Converting during downturns lets you move more shares for the same tax cost, with recovery happening in the Roth.
– State taxes: If you may relocate, compare state rules. Some states don’t tax retirement income; others do. Timing can save materially.
Account mechanics and rules you can’t ignore
– Access to funds:
– Traditional 401(k) to Roth IRA often requires an in-service rollover; many plans allow these at 59½. Some plans also allow in-plan Roth conversions earlier.
– If still working, check whether your plan offers a Roth 401(k) for new contributions. From 2024, designated Roth accounts in employer plans no longer have RMDs.
– Pro-rata rule: Applies to IRA conversions, not to dollars kept inside a 401(k). If you have any pre-tax IRA money and you convert from an IRA, the IRS treats all IRAs as one combined account for tax purposes. Plan the sequence of rollovers and conversions to avoid an unexpected tax bill.
– The two five-year rules:
– For Roth IRAs, earnings are tax- and penalty-free if it’s been at least five tax years since your first Roth IRA contribution/conversion and you’re 59½ or meet another qualifying condition.
– For conversions made before 59½, each conversion has its own five-year penalty clock on withdrawing the converted principal. After 59½, this penalty rule no longer matters.
– Estimated taxes: Large conversions often require quarterly estimates or increased withholding to avoid underpayment penalties. Safe harbor rules can protect you (generally 100% of last year’s tax, or 110% if last year’s AGI was over $150,000).
– Charitable giving: If you’re charitably inclined at 70½+, Qualified Charitable Distributions (QCDs) from IRAs can reduce taxable RMDs. That can be an alternative or complement to conversions.
– Company stock in your 401(k): If you hold employer stock with big unrealized gains, evaluate the Net Unrealized Appreciation (NUA) strategy before rolling to an IRA or converting; a conversion can forfeit NUA’s potential tax break.
A practical roadmap
1) Map your income now through age 75.
– Include wages/bonuses, pensions, rental income, dividends/interest, expected Social Security start age, and RMDs at 73/75.
2) Choose a target tax bracket for conversions each year.
– Run side-by-side scenarios: no conversions, modest bracket-filling, aggressive conversions through age 62, etc. A fee-only planner or tax pro with planning software can do this quickly.
3) Decide contribution mix today.
– If you’re still working and in a moderate bracket, consider shifting current deferrals partly or fully to Roth 401(k), especially through 2025 while rates are lower.
4) Plan the conversion calendar.
– Favor lower-income years, market dips, and pre-63 if you want to avoid IRMAA at 65. Consider accelerating in 2024–2025 before scheduled tax sunsets.
5) Coordinate taxes and cash flow.
– Set quarterly estimates or increase withholding from wages. Use taxable savings to pay the tax.
6) Revisit annually.
– Markets, brackets, and your income change. Adjust the conversion amount each year.
Rules of thumb
– If today’s marginal rate is equal to or below your realistic future marginal rate, a partial conversion is usually a win.
– If you expect to retire within 5–7 years and drop into a much lower bracket, wait and convert aggressively in early retirement before RMDs and Social Security.
– Don’t let the tax tail wag the dog. Even if a conversion triggers a temporary IRMAA surcharge or reduces ACA credits, the long-run math may still favor the move.
Bottom line
It’s not too early to start—especially if you can keep conversions in a moderate bracket and you expect higher taxes later due to RMDs, Social Security, or changing tax law. The optimal strategy is typically a series of partial, bracket-filling conversions over multiple years, coordinated with retirement timing, Medicare/ACA, and state taxes. Run projections (or have a professional do them) before you begin; small changes in timing and amount can materially improve your lifetime after-tax outcome.
This is general education, not tax advice. Consult a qualified tax professional who can model your specific income, state taxes, health insurance, and Social Security timing.
