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The Common Belief
Eight years. That is the entire runway between a 65th birthday and the first required minimum distribution at 73 — and as of September 28, 2026, that window is the single most valuable, most misunderstood asset on a retiree's balance sheet. The pitch making the rounds right now says to use it aggressively: drain a $900,000 traditional 401(k) into a Roth IRA before the IRS forces anything out. According to Google News, the framing originated with 24/7 Wall St., which built its piece around exactly that scenario — a $900,000 balance, emptied on purpose before the first RMD ever lands.
Our read: the goal is right, the word "empty" is wrong. The objective — lowering the lifetime tax bill rather than this year's — is sound and well-supported. But the instruction to zero out the account is a conclusion, not a calculation, and for a large share of the people reading it, the math points somewhere short of zero.
The Evidence: What the Window Is Actually Worth
Start with the goal, because everything else is arithmetic downstream of it. The goal is not "pay less tax in 2026." It is "pay less tax across the remaining 25 or 30 years, including the years a surviving spouse files alone." Those two goals recommend opposite actions, which is why conversion advice sounds contradictory depending on who is giving it.
The research puts a $900,000 balance at roughly $35,000 to $40,000 in annual RMDs once distributions begin at 73, all taxed as ordinary income. The IRS confirms the starting age: 73 for individuals who reach 72 after December 31, 2022, under the SECURE 2.0 Act, rising to 75 for those born in 1960 or later. The penalty for missing one is 25% of the amount not withdrawn — cut from 50% under the same law, though 25% of a $38,000 shortfall is still around $9,500, which is not a rounding error.
Now the part the surface reporting skips. Take the midpoint of that RMD range, $37,500, and divide it into the $900,000 balance. That is a distribution rate of about 4.2% — almost precisely the 4% rule's withdrawal figure. This is the non-obvious point: for a retiree who was already planning to live on roughly 4% of the portfolio, the RMD is not extra income at all. It is the income they were going to take anyway, just with the withdrawal schedule handed to them by the IRS instead of chosen by them. The tax bill in that case is not created by the RMD; it was always coming.
The RMD genuinely hurts a different person: the retiree whose pension, Social Security, and taxable-account dividends already cover the bills. For that household the forced $37,500 lands on top of income they did not need, stacking into a higher bracket for no spending benefit. That is the household the conversion strategy is actually built for — and neither the 24/7 Wall St. framing nor most of the advice circulating around it makes that distinction clearly.
The Math: Where the Brackets Break
Here is the calculation that decides the whole question, and it is one number wide: the spread between the tax rate paid on a conversion today and the rate that would have been paid on that same dollar later.
The research gives the raw inputs. For 2024, a married couple filing jointly could hold up to $94,300 in taxable income and remain inside the 12% bracket. Tax planning professionals quoted in the research note that converting during temporarily low-income years can mean paying 12% to 22% on converted amounts, against 24% to 32% or higher later, once RMDs and Social Security stack on top of each other.
Run it. A retiree with, say, $30,000 of taxable income in an early retirement year has roughly $64,300 of headroom below that $94,300 ceiling. Convert into that space and the marginal cost is 12 cents on the dollar. If that same dollar would later have come out at 24%, the spread is 12 percentage points — and on $64,300 of conversion, 12 points is about $7,700 of tax avoided on a single year's move. Repeat across an eight-year window and the headroom compounds into real money, without the portfolio itself earning a thing.
Chart: Marginal rates cited by tax planning professionals in the research — 12–22% on conversions made during low-income years, versus 24–32% or higher once RMDs and Social Security stack. The green bars are the cost; the blue bars are what is being avoided.
Notice what the chart makes obvious that a paragraph does not: the gap between "convert high" (22%) and "RMD era low" (24%) is two percentage points. Two. Once a conversion pushes into the upper band, the entire advantage nearly evaporates — and that is before the tax is paid, which brings up the piece almost nobody prices in.
Converting $900,000 over eight years means roughly $112,500 of income added per year. Even at a blended rate in the low 20s, that is tens of thousands of dollars in tax due annually — and if that tax is paid out of the 401(k) itself, the retiree is liquidating retirement assets to fund the conversion of retirement assets. The conversion only clearly wins when the tax is paid from a taxable account, because then the full pre-tax balance makes the jump into the Roth while the taxable account shrinks. Pay the tax from the 401(k) and the strategy quietly converts into an expensive wash.
Where a Careful Skeptic Pushes Back
The research itself flags the disagreement, and it deserves naming rather than smoothing over. Some sources advocate converting entire balances across five to eight years; others recommend permanent partial conversions to preserve tax diversification. That is not a minor quibble about pacing — it is a fundamental split about whether a zero balance in the traditional account is even desirable.
The case against emptying it: a traditional 401(k) balance is not purely a liability. It is the account that fills the standard deduction and the lowest brackets for free every single year, and it is the only account that can fund a qualified charitable distribution. Zero it out and every future dollar of spending has to come from the Roth or taxable side, which means the low brackets go unused — a permanent, recurring waste of cheap tax space. Forbes Advisor's contribution to this conversation, per the research, is precisely this kind of year-by-year bracket modeling rather than a single lump-sum verdict.
There is also the sequencing question that plan participants tend to discover too late: a Roth conversion is not a distribution, but it is income, and it can raise Medicare IRMAA surcharges and the taxable share of Social Security benefits in the year it happens. And once an RMD year arrives, the RMD must be satisfied first — it cannot itself be converted. The eight-year window is not a suggestion; it closes.
The scale context explains why any of this is being written about at all. The research cites over $7.3 trillion held in traditional IRAs and 401(k)s as of 2024, while Investment Company Institute data puts traditional IRA assets alone at approximately $13.5 trillion in 2023, with a substantial portion subject to future RMDs. Those figures measure different pools and should not be read as a contradiction — but together they describe a very large amount of money with a tax bill that has been deferred, not forgiven. The SECURE 2.0 Act of 2022 did not reduce that bill. It moved the due date and, in doing so, handed millions of retirees a longer window in which to choose their own rate.
The Habit That Makes It Work
Strategy is the easy part. The thing that separates a retiree who captures the spread from one who reads about it is a boring December routine, repeated eight times.
Every November or early December, total the year's taxable income and subtract it from the top of the target bracket — the $94,300 joint figure cited for 2024 is the reference point, adjusted for the current year's IRS inflation indexing. The difference is the conversion capacity. Convert up to it and stop. This is the financial planning equivalent of automating a contribution: do it once on the calendar and it beats willpower every time.
Hold the conversion amount to whatever a taxable brokerage or cash account can cover in tax. If the tax has to come out of the 401(k), the conversion is smaller than it looks and the math gets thin fast.
Choose in advance how much traditional balance to leave behind permanently — enough to absorb the standard deduction and the lowest brackets annually, plus any charitable giving plans. "Empty it" is a headline. A deliberate residual balance is a plan.
One note on tooling: the year-by-year bracket, IRMAA, and Social Security-taxation interactions are genuinely multivariable, and modern retirement-planning software and AI investing tools now run thousands of conversion sequences in seconds. They are useful for showing the shape of the answer. They are not a substitute for a CPA who can see the actual return, and no software knows what a reader's future tax rates will be — that is the one input the entire strategy rests on, and it is a guess.
Bottom Line
On balance, our analysis is that the conversion window between 65 and 73 is real and underused, but the "empty the account" framing oversells it. The strategy's value is concentrated in the low-bracket dollars — the 12-point spread, not the 2-point one — and it decays sharply as conversions push into higher brackets. The most likely outcome for a typical $900,000 household is not a zero balance but a materially smaller one, converted in measured annual slices, with the tax paid from outside the plan. This is a personal finance decision that compounds quietly for a decade, which is exactly the kind of unglamorous move that tends to outperform the dramatic version. Readers thinking about the broader income-versus-yield tradeoff in retirement will find a related breakdown in Smart Investor AI's comparison of dividend stocks and money market accounts.
Frequently Asked Questions
What is the required minimum distribution age for a 401(k) right now?
The IRS states the RMD starting age is 73 for individuals who reached age 72 after December 31, 2022, under the SECURE 2.0 Act. For those born in 1960 or later, the research indicates it rises to 75. Missing an RMD carries a penalty of 25% of the amount not withdrawn, reduced from 50% under the same law.
How much tax do you pay on a Roth conversion?
The converted amount is added to ordinary income for that year and taxed at the resulting marginal rates. Per the research, tax planning professionals cite 12% to 22% for conversions made during low-income years, versus 24% to 32% or higher once RMDs and Social Security stack. There is no separate conversion tax — it is ordinary income tax, which is why the timing matters so much.
Can I convert my entire 401(k) to a Roth IRA at once?
Mechanically yes, but a lump-sum conversion of a large balance pushes the full amount through the top brackets in a single year and can spike Medicare IRMAA surcharges. The research notes that strategic multi-year partial conversions are what keep retirees in lower brackets — which is why sources are split between full conversions over five to eight years and permanent partial conversions that preserve tax diversification.
Should I do a Roth conversion before taking Social Security?
Financial advisors commonly point to the window between retiring around 65 and the start of RMDs at 73 precisely because income is often temporarily low before Social Security is claimed. Once benefits begin, the conversion itself can increase the taxable portion of those benefits, narrowing the advantage. The sequencing is the strategy.
Disclaimer: This article is editorial commentary for informational purposes only and does not constitute financial, tax, or investment advice. It reflects analysis of publicly reported information and does not involve independent testing or individualized planning. Tax rules change and individual circumstances vary; consult a qualified tax professional before executing a Roth conversion. Research based on publicly available sources current as of September 28, 2026.