Roth Conversion Strategy 2026: There Is No Deadline — What Actually Decides It

Short answer: there is no closing window. The 2017 tax cuts were legislated to expire on 31 December 2025, with the top rate reverting to 39.6%. That did not happen. The One Big Beautiful Bill Act (OBBBA), Public Law 119-21, signed 4 July 2025, made the individual rate structure permanent. The 2026 brackets are 10%, 12%, 22%, 24%, 32%, 35% and 37% — the same seven rates, inflation-adjusted (Rev. Proc. 2025-32). No rate increase is scheduled, and no date is attached to anything on this page.

Correction notice (updated 30 July 2026). Earlier versions of this page said current rates "may revert to higher rates (28%+) after 2025" and urged conversions before that happened. Both halves were wrong: the reversion was cancelled a year before this page was written, and 28% is a pre-2018 bracket that does not appear in any current or scheduled rate schedule. If you accelerated a conversion because of that framing, please read the note at the end of this page — a Roth conversion cannot be undone. Recharacterisation of conversions was repealed by TCJA §13611 for conversions made after 2017, so unlike a gift or a trust, there is no version of this you can restructure later. That is precisely why a manufactured deadline does real damage here.

This page has been rebuilt around the things that actually decide a conversion. None of them is a date.

The Only Question That Matters

A Roth conversion moves money from a traditional IRA or 401(k) into a Roth account. You pay income tax on the converted amount this year; everything after that is tax-free.

Strip away the noise and a conversion is a single bet: is your tax rate on this dollar today lower than it will be on the day you would otherwise have withdrawn it? If yes, convert. If no, don't. Everything else on this page is a refinement of that one comparison.

The comparison, done properly

Convert $100,000 while you are in the 22% bracket, paying the $22,000 of tax from a taxable account rather than from the IRA. Suppose the money grows fivefold to $500,000 by the time you need it, and you would have withdrawn it in the 35% bracket.

Net benefit: $65,000.

Two things are worth noticing, because a lot of published conversion maths gets both wrong.

First, you must credit the traditional path with the tax you didn't pay. If you skip the conversion, the $22,000 stays invested. Comparing $175,000 of future tax against $22,000 of present tax — subtracting a 2026 dollar from a 2039 dollar — overstates the benefit badly. An earlier version of this page did exactly that and reported the benefit as $153,000, about 2.4 times the real figure.

Second, there is a shortcut that makes the answer checkable. When the conversion tax comes from outside the account, the entire benefit is the rate differential applied to the final balance:

(withdrawal rate − conversion rate) × final balance = (35% − 22%) × $500,000 = $65,000

Same answer, no projection required. If a conversion analysis you are reading does not reduce to this identity, it has an error in it. And notice what the identity implies: the size of the account and the growth rate do not change whether a conversion is a good idea. They only change how much a good idea is worth. Only the two rates decide the sign.

When Conversions Make Sense

1. You're in a low-income year — early retirement, a sabbatical, a job change, a business start-up. This is the single most reliable case, because you can see the low rate rather than forecast it.
2. Your withdrawal-year bracket will be higher than today's — large expected RMDs, a pension starting later, both spouses' Social Security switching on.
3. You want to shrink future RMDs. Traditional balances are taxed on the IRS's schedule from 73, not yours. Roth IRAs have no RMDs for the owner, and since 2024 neither do Roth 401(k)s (SECURE 2.0 §325).
4. You want to protect a surviving spouse. See the widow's-bracket section below — this is the most underrated reason on the list.
5. You have access to the backdoor Roth. If you earn too much to contribute to a Roth directly, a non-deductible traditional contribution plus a conversion gets you there — subject to the pro-rata rule below.

When they don't

1. You're in your peak earning years at 35–37%. You are locking in the highest rate you will ever pay.
2. Your retirement income will be genuinely low. If you will draw at 12% and convert at 24%, converting costs you money. This is common and under-discussed.
3. You'd have to pay the tax out of the IRA. That guts the arithmetic above — and if you are under 59½, the withheld amount is itself an early distribution subject to the 10% penalty.
4. The conversion pushes you across an IRMAA threshold and the surcharge outweighs the rate gap.
5. You are on a marketplace health plan. A conversion raises the household MAGI that sets your premium tax credit. For an early retiree bridging to Medicare this can cost more than the income tax on the conversion. Model it before converting, not after.

What is not a reason

A scheduled rate increase. There isn't one. "Rates could rise someday" remains perfectly true — a future Congress can raise them in any year it likes — but that is an argument for holding some Roth as diversification against an unknown future, not for converting a particular amount before a particular date. Permanent is a drafting term, not a promise. It is also not a deadline.

Filling the Lower Brackets

The most reliable conversion strategy is to convert exactly enough to reach the top of a bracket you are happy to pay, and stop.

Worked example: age 62, single

Income: $50,000 part-time wages + $5,000 interest = $55,000 Less the 2026 single standard deduction: $16,100 Taxable income: $38,900

2026 single brackets: 10% to $12,400 · 12% to $50,400 · 22% to $105,700.

Room remaining in the 12% bracket: $50,400 − $38,900 = $11,500.

This is the step most often got backwards. The room is the distance from your taxable income up to the ceiling — not the part of the bracket you have already used. An earlier version of this page computed the amount already consumed and told readers to convert that instead, which would have pushed roughly $21,000 into the 22% bracket at nearly double the intended rate.

• Convert $11,500. Tax: $11,500 × 12% = $1,380.
• Left alone, that $11,500 grows at 6% for 13 years to age 75: × 1.06¹³ = ×2.133 = $24,529.
• Withdrawn then in the 22–24% range, say 24%, the tax would be $5,887.
• Benefit, by the identity above: (24% − 12%) × $24,529 = $2,943 at 75, which is $1,380 in 2026 dollars.

That last line is the sanity check: the benefit in today's money is exactly the tax you paid, because the rate gap (12 points) happens to equal the rate you paid. Convert one dollar more and it is taxed at 22%, cutting the gap from 12 points to 2 and making the exercise almost pointless.

The IRMAA Threshold

If you are on Medicare, a conversion inflates the MAGI that sets your Part B and Part D premiums — and IRMAA is a cliff, not a slope. One dollar over a threshold triggers the full surcharge for that tier.

For 2026, the standard Part B premium is $202.90/month, and the single-filer tiers are:

The two-year lookback. 2026 premiums are set from 2024 income. So a conversion made in 2026 shows up in your 2028 premiums, and nowhere before then. Two consequences follow, and they cut in opposite directions:

• You will not feel the cost for two years, which makes it easy to convert into a surcharge without noticing.
• The surcharge applies for one year only. IRMAA is recalculated annually from a single year's return. A one-off conversion produces a one-off surcharge, not a permanent one.

Worked example

Age 65, on Medicare, 2026 MAGI of $100,000 before converting. Convert $50,000 → MAGI $150,000, which crosses two thresholds and lands in the $137,001–$171,000 tier.

• Income tax on the conversion at 22%: $11,000
• Part B surcharge: ($405.80 − $202.90) × 12 = $2,435, in 2028 only
• Plus a Part D surcharge, which applies on the same tiers
• Total: roughly $13,400, not the $11,000 the bracket alone suggests

Convention: 2028 thresholds and premiums have not been published. The 2026 figures above show the shape and scale of the effect, not a prediction of the 2028 bill.

The actionable version: from a $100,000 base, converting $9,000 takes you to exactly $109,000 and stays inside the base tier. Converting $9,001 does not. If you are near a threshold, the last few thousand dollars of a conversion can be the most expensive money you will ever move.

RMD Pressure: The Real Clock

There is no legislative deadline. There is a biological one, and it is the strongest argument on this page.

At 73, required minimum distributions begin. From that point the IRS decides how much of your traditional balance becomes taxable income each year. Ages roughly 60 to 72 are the only stretch in most people's lives when income is low and RMDs have not started — and that window closes on your birthday regardless of what Congress does.

Worked example: the ladder

Model, stated so you can check it. Single filer, retires at 60 with a $600,000 traditional IRA and $30,000 of part-time income, claims Social Security at 70, IRA grows at 6%. All figures in 2026 dollars: brackets and the standard deduction are inflation-indexed, so holding both fixed is the like-for-like convention.

Taxable income before converting: $30,000 − $16,100 = $13,900. Room to the top of the 12% bracket: $36,500 a year.

Not converting doubles the balance the RMD rules get to work on, and doubles the first RMD. A $48,293 RMD on top of $40,000 of Social Security lands squarely in the 22% bracket; the $25,373 RMD leaves considerably more room below it.

What the ladder is worth: $365,000 moved out at 12% instead of 22% is a 10-point saving — $36,500 in 2026 dollars. That is the whole claim, and it is one multiplication. It holds only if the withdrawal-year rate really would have been 22%; if your retirement bracket turns out to be 12%, the ladder was a wash, and if it turns out to be 10%, it cost you money.

The Widow's Bracket

The single most overlooked reason to convert, and the one with no deadline attached whatsoever — it is triggered by a death, not a date.

When one spouse dies, the survivor files as single from the following tax year. The brackets roughly halve in width and the standard deduction nearly halves. The IRA does not.

Couple, both 75, married filing jointly:

• RMDs $60,000 + Social Security $50,000 (85% taxable, $42,500) = AGI $102,500
• Standard deduction, both 65+: $32,200 + $3,300 = $35,500 → taxable $67,000
• MFJ 12% bracket runs to $100,800 → marginal rate 12%, tax $7,544

One spouse dies. The survivor keeps the whole IRA and the larger of the two Social Security benefits:

• RMDs $60,000 + Social Security $30,000 (85% taxable, $25,500) = AGI $85,500
• Standard deduction, single 65+: $16,100 + $2,050 = $18,150 → taxable $67,350
• Single 22% bracket runs $50,401–$105,700 → marginal rate 22%, tax $9,529

Household income fell by $17,000 and the tax bill rose by $1,985. The marginal rate nearly doubled. Every dollar still sitting in the traditional IRA is now taxed on the single schedule for the rest of the survivor's life, and every conversion made while both spouses were alive was made at the wider brackets.

The Two Five-Year Rules

These are routinely merged into one rule, and the merged version is wrong in both directions. There are two clocks, and they do different jobs.

Rule 1 — the earnings clock. One per person, for life. Earnings come out tax-free only if the distribution is qualified: you are 59½ or older (or it is death, disability, or a first home) and five tax years have passed since 1 January of the year of your first ever contribution or conversion to any Roth IRA. It is a single lifetime clock across all your Roth IRAs. It does not restart when you open a new account, and it is not per-account.

Rule 2 — the conversion clock. One per conversion. Each conversion starts its own five-year clock, and it governs exactly one thing: whether the 10% early-distribution penalty applies if you pull the converted principal back out before five years are up. It stops applying entirely once you reach 59½.

What that means in practice

• Convert $50,000 in 2026 at age 60, first Roth opened in 2015. Both clocks are satisfied. Principal and earnings are available immediately, tax- and penalty-free.
• Same conversion, but 2026 is your first ever Roth. You are past 59½, so the conversion clock does not bind — the $50,000 of principal is available straight away. But earnings are not qualified until 1 January 2031.
• Convert at 55. Now the conversion clock matters: withdrawing that principal before 2031 triggers the 10% penalty even though the principal was already taxed on conversion.

The practical takeaway for anyone over 59½ who has held a Roth for five years is that neither rule constrains you — and for anyone opening a first Roth late, the fix is to start the earnings clock now with any contribution or conversion, however small, rather than to rush the size of it.

The Pro-Rata Rule

The most expensive trap in conversions, and the most commonly mis-stated.

What actually aggregates. Under IRC §408(d)(2), all your traditional, SEP and SIMPLE IRAs are treated as one account when working out how much of a conversion is taxable. Roth balances are not part of this calculation, and neither are 401(k) or 403(b) balances. Basis is tracked on Form 8606.

Example. You hold a traditional IRA of $1,000,000, of which $100,000 is after-tax basis from non-deductible contributions and $900,000 is pre-tax. You convert $100,000, expecting it to be the after-tax part. You cannot choose:

• Taxable share: $900,000 ÷ $1,000,000 = 90%
• Of the $100,000 converted: $90,000 is taxable income, $10,000 is tax-free
• Tax owed, at a 24% marginal rate: $21,600

Note the distinction, because getting it wrong is alarming: $90,000 is the taxable amount, not the tax. An earlier version of this page reported it as the tax bill, which would make a $100,000 conversion cost $90,000 — roughly four times the real figure.

The workaround

Employer plans sit outside the §408(d)(2) aggregation. If your 401(k) accepts incoming rollovers:

1. Roll the $900,000 pre-tax into the 401(k). Plans generally may not accept after-tax IRA basis — which is exactly what makes this work: the basis is left behind.
2. The traditional IRA now holds $100,000, all basis.
3. Convert it. Taxable share: 0%.

Timing matters: the pro-rata fraction is measured on 31 December of the conversion year, not on the conversion date. The rollover must land before year end or the whole exercise fails.

How to Actually Do It

1. Project this year's income from every source, and be honest about a spouse's income and any capital gains you expect to realise.
2. Find the ceiling of the bracket you're willing to pay and subtract your projected taxable income. That difference — not the part of the bracket you've used — is your conversion room.
3. Check the thresholds that sit between you and that ceiling. IRMAA if you're on Medicare or within two years of it; the ACA premium tax credit if you're on a marketplace plan; the capital gains 0%-to-15% threshold if you were planning to realise gains this year.
4. Confirm you can pay the tax from outside the account. If you can't, the arithmetic above does not apply to you.
5. Execute a direct trustee-to-trustee transfer. Not a 60-day indirect rollover — the rules are unforgiving and the withholding is a trap. Your custodian issues a Form 1099-R.
6. File Form 8606 with your return and pay via estimated tax or increased withholding to avoid an underpayment penalty.
7. Re-run the whole calculation next year. Your income will differ, and the brackets will have moved with inflation.

Convert late in the year, not early. By November you know your actual income; in February you are guessing. And because the conversion is irreversible, a guess is the one thing you cannot afford — see below.

If You Already Converted Because of the "Deadline"

This is the part that needs saying plainly, because the recharacterisation escape hatch no longer exists.

Before 2018, a conversion could be undone. You could recharacterise it back to a traditional IRA up until the extended due date of the return, which meant a conversion made on a wrong premise could simply be reversed. TCJA §13611 repealed that for conversions made after 31 December 2017. There is no unwind.

So if you converted more than you otherwise would have, in order to beat a rate increase that never came:

• Nothing can be reversed, and nothing needs to be hidden. It was the correct response to the law as widely described at the time.
• The conversion may still have been right. Everything on this page — the bracket comparison, RMD pressure, the widow's bracket — argues for conversions on grounds that never depended on the sunset. Check your conversion against those instead. Many will still pass.
• What you may have got wrong is the size and the timing, not the decision. Deadline-driven advice pushed people to convert large amounts in a single year. Spreading the same total across several years usually costs less tax, and there is now no reason not to.
• If a conversion pushed you over an IRMAA threshold, the surcharge lands two years later and lasts one year. It is worth knowing it is coming rather than being surprised by it.
• Stop the ladder if the premise was the only reason for it. If you set up a multi-year conversion schedule sized to finish before 2026, there is nothing to finish before.

Key Takeaways

1. There is no deadline. OBBBA made the TCJA rates permanent; the 39.6% reversion was cancelled. Any advice urging you to convert before rates rise is describing a law that no longer exists.
2. A conversion is one comparison: your rate today versus your rate on the day you would have withdrawn. The benefit is (withdrawal rate − conversion rate) × final balance. If an analysis doesn't reduce to that, it's wrong.
3. Compute bracket room as the distance to the ceiling, not the part already used.
4. IRMAA is a cliff with a two-year lag and a one-year duration. Check the thresholds before converting, not after.
5. The real clock is RMDs at 73, and it is set by your birthday, not by Congress.
6. The widow's bracket may be the strongest single argument for converting while both spouses are alive.
7. Two five-year rules, not one: a lifetime earnings clock, and a per-conversion penalty clock that stops mattering at 59½.
8. Pro-rata aggregates traditional/SEP/SIMPLE IRAs only — Roth balances are not in the fraction, and the taxable amount is not the tax.
9. Conversions are irreversible. Recharacterisation was repealed by TCJA §13611. Convert late in the year, when you know your income, and never because of a date.

Sources: Rev. Proc. 2025-32 (2026 brackets, standard deduction) · One Big Beautiful Bill Act, P.L. 119-21 (4 July 2025) · Tax Foundation, 2026 tax brackets · IRC §408(d)(2) (pro-rata) · IRC §408A(d)(2) and §408A(d)(3)(F) (five-year rules) · TCJA §13611 (recharacterisation repeal) · SECURE 2.0 §325 (Roth 401(k) RMDs).