Can You Convert a SEP-IRA to a Roth IRA? (w/Examples) + FAQs

This article reflects federal rules as of June 2026 and covers tax year 2025 (filed in 2026), with 2026 figures noted where finalized. State rules vary and are addressed in their own section. Tax law changes — confirm current figures with IRS.gov before you file.

Yes. For tax year 2025, you can convert a SEP-IRA to a Roth IRA. A SEP-IRA is treated as a traditional IRA, so the same Roth conversion rules apply. You pay ordinary income tax on the pre-tax amount you convert in the year you convert it.

That single conversion can hand you a four- or five-figure tax bill this April, because every pre-tax dollar you move counts as taxable income for the year. The bigger trap is the pro-rata rule, which can tax part of a conversion you thought was tax-free, and the December 31 deadline, which gives you no extra time the way a contribution does.

Self-employed savers are moving fast on this. Fidelity reported record Roth conversion volume in recent years as savers lock in today’s tax rates. Get the order of operations wrong and you can owe tax twice on the same money, miss the deadline, or trip a penalty.

Here is what you will learn:

✅ Whether your SEP-IRA qualifies for a Roth conversion and the exact steps to do it
🧮 How the pro-rata rule can tax a conversion you thought was tax-free — with the math
📅 The hard December 31 deadline and how it differs from the contribution deadline
💸 Three fully worked dollar examples, including a multi-year conversion ladder
⚠️ The 5-year rule, common mistakes, and exactly when to call a CPA

What a SEP-IRA and a Roth IRA Actually Are

A SEP-IRA (Simplified Employee Pension) is a retirement account for self-employed people and small-business owners. You fund it with pre-tax dollars, deduct the contribution now, and pay tax later when you take the money out. The IRS treats a SEP-IRA as a traditional IRA for tax purposes, which is the key fact that makes a Roth conversion possible.

A Roth IRA is the mirror image. You fund it with after-tax dollars, get no deduction now, and then withdraw the money — including all the growth — completely tax-free in retirement, as long as you follow the rules. There are also no required minimum distributions (RMDs) on a Roth IRA during your lifetime, while a SEP-IRA forces you to start withdrawing at age 73.

A Roth conversion is the bridge between the two. You move money from the pre-tax SEP-IRA into the after-tax Roth IRA, and you settle up with the IRS now by paying income tax on the converted amount. You are trading a tax bill today for tax-free growth and withdrawals later.

Why does this matter? Because the conversion is a one-way, taxable event with no income limit. Anyone can do it, regardless of how much they earn. The consequence of converting is a higher taxable income for that one year. A real example: Maria, a freelance designer, converts $40,000 from her SEP-IRA in 2025. That $40,000 stacks on top of her other income and is taxed at her marginal rate. A common misconception is that the conversion is “free” because it stays inside a retirement account — it is not; the tax is due with your 2025 return. What you should do: estimate the tax before you convert, and never convert more than you can afford to pay tax on from outside the account.

The Big One: The Pro-Rata Rule

The pro-rata rule is the single most important concept in any SEP-IRA conversion, and it is where most people get hurt. It decides how much of your conversion is taxable when your IRAs hold a mix of pre-tax and after-tax money.

How the Pro-Rata Rule Works

Under the pro-rata rule explained by Ed Slott, the IRS will not let you cherry-pick and convert only your after-tax (non-deductible) dollars tax-free. Instead, every dollar you convert is treated as a blend of pre-tax and after-tax money, based on the ratio across all your traditional, SEP, and SIMPLE IRAs combined as of December 31.

The formula is the after-tax basis divided by the total year-end balance of all those IRAs. That percentage is the tax-free share of your conversion; the rest is taxable. The consequence of ignoring this is a surprise tax bill on money you believed was already taxed. The next step is to add up every IRA you own — not just the SEP — before you calculate anything.

The Aggregation Trap

The rule looks at all of your IRAs as if they were one giant account. This catches people doing a “backdoor Roth” who forget they have a SEP sitting at another brokerage. A real example: David has a $6,000 non-deductible traditional IRA he plans to convert tax-free, but he also has a $54,000 SEP-IRA. Because the IRS aggregates the two, only 10% of his conversion ($6,000 / $60,000) is tax-free. The misconception is that separate accounts are taxed separately. What to do: move the SEP into a solo 401(k) first if your plan allows it, because employer plan balances are excluded from the pro-rata math.

How to Avoid Pro-Rata Pain

The cleanest fix is to roll your pre-tax SEP money into a solo 401(k) or other employer plan, leaving only after-tax dollars in your IRAs before converting. The consequence of skipping this step is paying tax on a share of your conversion you did not need to. The other option is simply to convert the entire SEP balance and accept that the full pre-tax amount is taxable this year. What to do next: decide before December 31, because the rule measures your balances on the last day of the year.

Which Situation Applies to You?

The right move depends on what else is in your accounts. Find your case below and follow that path.

Your SEP is your only IRA and it is all pre-tax. Simplest case. The full converted amount is taxable. Skip the pro-rata worry and focus on tax timing.
You have a SEP plus a non-deductible traditional IRA. The pro-rata rule applies. Consider rolling the SEP into a solo 401(k) first to isolate your after-tax dollars.
You have employees in your SEP plan. Your conversion only touches your own account, but converting does not affect your duty to fund employee accounts. Talk to a CPA.
You want a Roth SEP going forward. Since 2023, SECURE 2.0 allows Roth SEP contributions directly, sidestepping future conversions entirely.
You are near a tax-bracket or IRMAA cliff. Convert in smaller annual slices (a “conversion ladder”) to avoid jumping a bracket or raising Medicare premiums.

The Roth SEP Alternative (SECURE 2.0)

Before you convert, know that you may not need to. Since January 1, 2023, Section 601 of the SECURE 2.0 Act lets employers offer a Roth SEP-IRA, where contributions go in as after-tax money from the start.

A Roth SEP contribution is included in your gross income the year you make it, exactly like a Roth IRA contribution, but it grows tax-free afterward. The consequence of using this route is that you avoid the pro-rata rule and the lump-sum conversion tax bill entirely, because the money was never pre-tax. A real example: Priya, a consultant, elects Roth treatment on her 2025 SEP contributions, so there is nothing to convert later.

The catch is that your plan and custodian must actually offer the Roth SEP option, and you must affirmatively elect it before the contribution is made — retroactive elections are not allowed. Employer Roth SEP contributions are reported on Form 1099-R in the year allocated. A common misconception is that every custodian supports this; many still do not. What to do: ask your provider in writing whether Roth SEP contributions are available before you commit.

Roth SEP vs. Traditional SEP-to-Roth Conversion

These two paths reach the same destination but feel very different at tax time.

Feature	Roth SEP Contribution
When you pay tax	On each contribution as you make it, spread across the year
Pro-rata rule risk	None — money is after-tax from day one
Big one-time tax bill	No; tax is built into ordinary contribution income
Availability	Only if your custodian and plan support it (post-2023)
Best for	Savers who want Roth money going forward without a conversion

Feature	SEP-to-Roth Conversion
When you pay tax	All at once, in the year you convert
Pro-rata rule risk	High if you hold other pre-tax IRA money
Big one-time tax bill	Yes, on the full pre-tax amount converted
Availability	Always allowed; no income limit
Best for	Moving an existing SEP balance into Roth status

Worked Examples (the Real Math)

Numbers make this concrete. Each example uses 2025 federal tax brackets for a single filer and rounds for clarity.

Example 1 — Clean Full Conversion, No Other IRAs

Sam is single, self-employed, and has one account: a $50,000 SEP-IRA, all pre-tax. His other 2025 taxable income is $70,000, putting him in the 22% bracket. He converts the whole $50,000.

All $50,000 is taxable because there is no after-tax basis. Stacked on his income, most of it lands in the 22% and 24% brackets, costing roughly $11,200 in federal tax. The consequence is a one-time bill he pays from his savings account, not from the SEP. What he did right: he paid the tax with outside cash, so the full $50,000 keeps growing tax-free.

Example 2 — Partial Conversion Hit by Pro-Rata

Lena has a $54,000 pre-tax SEP-IRA and a $6,000 non-deductible traditional IRA, for $60,000 total. She converts $20,000, expecting the $6,000 basis to shield her.

Her after-tax share is $6,000 / $60,000 = 10%. So only 10% of her $20,000 conversion ($2,000) is tax-free; the other $18,000 is taxable. In the 24% bracket, that is about $4,320 in tax. The misconception was that she could convert “just the after-tax part.” What she should have done: roll the SEP into a solo 401(k) first, leaving only the $6,000 basis to convert tax-free.

Example 3 — Multi-Year Conversion Ladder

Tom, age 60, has a $200,000 SEP-IRA and wants it all in Roth without spiking into a high bracket. Converting it all in 2025 would push him into the 32% bracket.

Instead, he converts about $40,000 a year for five years, keeping each year inside the 24% bracket. He pays roughly $9,600 in tax per year instead of a much larger lump-sum bill at a higher marginal rate. The consequence of spreading it out is lower lifetime tax and no IRMAA Medicare surcharge spike. What he did: he mapped his bracket headroom each year before converting.

How to Convert: Step-by-Step

A SEP-to-Roth conversion is mostly paperwork, but each step has a consequence if skipped.

Open a Roth IRA at the same custodian if you can, to make the transfer instant and avoid mailing checks.
Decide the amount. Pick a number that keeps you inside your target tax bracket for 2025.
Request the conversion as a direct (trustee-to-trustee) transfer, so no money touches your hands and no withholding is forced.
Choose tax withholding carefully. Do not withhold tax from the converted amount if you can pay from outside cash, because withheld dollars under age 59½ count as an early withdrawal and can be penalized.
Pay estimated tax if the conversion is large, to avoid an underpayment penalty when you file.
Report it on Form 8606, Part II, with your Form 1040. This is mandatory.

Filling Out Form 8606

Form 8606, Nondeductible IRAs, is how you report the conversion and protect your basis. On Line 16 you enter the net amount converted. On Line 17 you enter your nontaxable basis (from Part I). On Line 18 you subtract Line 17 from Line 16 — that taxable result flows to Form 1040, line 4b. The consequence of skipping this form is paying tax twice on your after-tax dollars, because the IRS will not know you had any basis. If you file electronically, your software generates it; if you file by paper, attach it. The deadline is your tax-filing deadline. See our guide on how to fill out Form 8606 for a line-by-line walkthrough.

Deadlines, Costs, and Timing

The conversion deadline is December 31, 2025, to count for tax year 2025 — there is no grace period into April. This is the most misunderstood point, because IRA contributions can be made until the April filing deadline, but conversions cannot. The consequence of missing December 31 is that the income lands in the next tax year instead, which may wreck your bracket planning.

Most conversions are free at the custodian and process in one to several business days when both accounts are at the same firm. There is no IRS fee. Your real cost is the income tax, plus a CPA’s fee — often $200 to $600 — if you want help projecting the tax hit. What to do: initiate the conversion by mid-December at the latest, since custodians get backlogged at year-end.

The 5-Year Rule on Converted Money

The 5-year rule for conversions is separate from the rule on Roth contributions, and confusing them costs people penalties. Under the conversion 5-year rule, each conversion has its own five-year clock that starts January 1 of the conversion year.

If you are under age 59½ and withdraw converted principal before that conversion’s five years are up, you owe a 10% early-withdrawal penalty on it, even though you already paid income tax. A real example: Carlos, 52, converts $30,000 in 2025 and pulls it out in 2027 — he owes a $3,000 penalty. The misconception is that paying conversion tax makes the money instantly accessible. If you are over 59½, this conversion clock no longer applies to you. What to do: leave converted dollars untouched for five years, or until 59½, whichever comes first.

A second, separate clock governs whether your earnings come out tax-free, which requires both five years since your first Roth and age 59½, as Fidelity outlines.

Federal vs. State: Does Your State Tax the Conversion?

Start with the federal rule: the converted pre-tax amount is ordinary income on your federal return. Your state may or may not follow. Never assume conformity.

State Type	How It Treats the Conversion
No income tax (e.g., Florida, Texas, Nevada, Washington)	The conversion is not taxed at the state level at all
High-tax states (e.g., California)	The conversion is fully taxable as state income, on top of federal
Most other states	Generally follow the federal treatment and tax the converted amount

In a no-income-tax state, only the federal bill applies, which is a genuine advantage for retirees who relocate before converting. In California, the conversion adds to state taxable income and can be taxed up to the top state rate, sharply raising the total cost. The consequence of ignoring state tax is under-withholding and a state penalty. What to do: check your state Department of Revenue’s IRA guidance, or ask a local CPA, before you convert a large balance.

Mistakes to Avoid

Forgetting other IRAs in the pro-rata math. You owe tax on a conversion you thought was shielded.
Withholding tax from the conversion under age 59½. The withheld amount becomes a penalized early withdrawal.
Missing the December 31 deadline. The income shifts to the wrong tax year and breaks your plan.
Converting too much in one year. You jump a tax bracket or trigger an IRMAA Medicare surcharge.
Paying the tax from the converted money. You shrink the Roth and may owe a penalty on the shortfall.
Skipping Form 8606. You lose track of basis and risk paying tax twice on after-tax dollars.
Confusing the contribution and conversion deadlines. You assume you have until April; you do not.
Ignoring state tax. A surprise state bill and possible underpayment penalty hit at filing.

Do’s and Don’ts

Do total every traditional, SEP, and SIMPLE IRA before calculating the taxable amount, because the pro-rata rule aggregates them all.
Do pay the conversion tax from outside cash, so your full balance keeps compounding tax-free.
Do use a direct trustee-to-trustee transfer, to avoid forced withholding and the 60-day redeposit risk.
Do file Form 8606, because it is the only record of your basis.
Do consider spreading conversions over several years, to control your bracket and Medicare costs.
Don’t convert more than you can pay tax on, because you cannot easily undo a conversion since recharacterization was repealed.
Don’t assume your state follows federal rules, because conformity varies widely.
Don’t withdraw converted funds within five years if you are under 59½, to dodge the 10% penalty.
Don’t wait until late December, because custodians get backlogged and a missed deadline cannot be fixed.
Don’t forget RMDs, because you must take any required SEP distribution before converting if you are 73 or older.

Pros and Cons of Converting

Pro — Tax-free growth. Every future dollar of growth comes out tax-free in retirement, which can dwarf the upfront tax.
Pro — No lifetime RMDs. A Roth IRA never forces withdrawals on you, unlike a SEP-IRA at age 73.
Pro — No income limit. Anyone can convert, even high earners locked out of direct Roth contributions.
Pro — Tax-rate hedge. You lock in today’s rates if you expect higher rates later.
Pro — Better for heirs. Beneficiaries inherit tax-free Roth money instead of a taxable SEP.
Con — Upfront tax bill. The full pre-tax amount is taxed now, which can be a large one-year hit.
Con — Bracket and IRMAA risk. A big conversion can push you into a higher bracket or raise Medicare premiums.
Con — Pro-rata complexity. Other pre-tax IRAs can make part of a “tax-free” conversion taxable.
Con — No do-overs. Recharacterization of conversions was repealed, so the move is permanent.
Con — Five-year lock. Under 59½, converted funds carry a penalty clock for five years.

When to Call a Professional

This is educational information, not advice for your specific situation. A SEP-to-Roth conversion is simple when the SEP is your only IRA and the amount is modest. It gets complex fast when you hold multiple IRAs, run a SEP with employees, are near a bracket or IRMAA cliff, or want a multi-year ladder.

In those cases, a CPA or tax attorney can project the exact tax, model the pro-rata impact, and time the conversion. That help usually runs a few hundred dollars and can save many times that in avoided tax mistakes.

What to Do Next

List every IRA you own — traditional, SEP, and SIMPLE — with year-end balances and any after-tax basis.
Calculate your pro-rata percentage if you hold any after-tax dollars.
Pick a conversion amount that keeps you inside your target 2025 bracket.
Open the Roth IRA and request a direct conversion with zero withholding.
Set aside the tax in cash and pay estimated tax if the amount is large.
File Form 8606 with your 2025 return, and keep a copy forever.
Initiate the conversion by mid-December 2025 to beat the December 31 deadline.

For related reading, see our guides on the backdoor Roth IRA, traditional vs. Roth IRA, and the Roth conversion ladder.

FAQs

Can you convert a SEP-IRA to a Roth IRA?

Yes. For tax year 2025, a SEP-IRA is treated as a traditional IRA, so you can convert any amount to a Roth IRA. You pay ordinary income tax on the pre-tax dollars in the conversion year.

Is there an income limit to convert a SEP to a Roth?

No. There is no income limit on Roth conversions for tax year 2025. Anyone can convert, regardless of earnings, which is why high earners use conversions instead of direct Roth contributions.

How much tax will I owe on the conversion?

Your ordinary income tax rate on the pre-tax amount. The converted sum stacks on your other 2025 income and is taxed at your marginal bracket — federally from 10% up to 37%.

What is the deadline to convert for 2025?

December 31, 2025. Unlike IRA contributions, conversions get no extension into April. The money must leave the SEP by year-end to count for tax year 2025.

Does the pro-rata rule apply to a SEP conversion?

Yes. The IRS aggregates all your traditional, SEP, and SIMPLE IRAs to find the taxable share. You cannot convert only after-tax dollars if you also hold pre-tax IRA money.

Can I convert just part of my SEP-IRA?

Yes. Partial conversions are allowed and common. Many savers convert smaller amounts over several years to avoid jumping into a higher tax bracket.

Do I have to report the conversion to the IRS?

Yes, on Form 8606. You report the conversion in Part II and attach it to your Form 1040. Skipping it risks paying tax twice on any after-tax basis.

Will I owe a 10% penalty for converting before age 59½?

No, not on the conversion itself. The conversion is penalty-free, but withdrawing the converted funds within five years while under 59½ can trigger a 10% penalty.

Can I avoid the conversion tax with a Roth SEP instead?

Yes, going forward. Since 2023, SECURE 2.0 lets eligible plans accept after-tax Roth SEP contributions, so new money never needs converting — if your custodian offers it.

Does my state tax a Roth conversion?

It depends. No-income-tax states like Florida and Texas do not tax it. Most other states, including California, treat the converted amount as taxable state income.

Can I undo a Roth conversion if I change my mind?

No. Recharacterization of conversions was repealed by the 2017 tax law. Once you convert, the move is permanent, so convert only what you are sure about.

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