SEP & SIMPLE IRA Pro Rata Rule: Backdoor Roth

Wondering whether SEP and SIMPLE IRAs count for the pro-rata rule when you run a backdoor Roth? For a self-employed saver or freelancer, the answer is yes: both employer-style IRAs are pulled into the same aggregation pool as any traditional or rollover IRA, and they are the accounts most likely to quietly make a Roth conversion taxable.

Last reviewed: August 2026 | Written and reviewed by Craig Wear, CFP®, founder of Q3 Advisors

Yes: SEP and SIMPLE IRAs both count for the pro-rata rule

SEP and SIMPLE IRAs both count for the pro-rata rule because the tax code treats each as a traditional IRA. Their pre-tax balances combine with any other traditional or rollover IRA when the pro-rata fraction is computed under IRC section 408(d)(2). For a backdoor Roth, that combined balance usually decides how much tax you owe. This page narrows the general pro-rata rule for Roth conversions to the self-employed case.

Why a SEP IRA counts even though it feels like a work plan

A SEP IRA (Simplified Employee Pension) counts because, despite the employer-funded label, the assets legally sit inside a traditional IRA. Contributions are pre-tax, growth is tax-deferred, and distributions are taxed as ordinary income, exactly like a plain traditional IRA. The code draws no distinction, so a SEP balance folds into the pro-rata calculation dollar for dollar. A freelancer with a healthy SEP who attempts a clean backdoor Roth often finds the conversion is mostly taxable.

Why a SIMPLE IRA counts too (and the 2-year nuance)

A SIMPLE IRA (Savings Incentive Match Plan for Employees) is a traditional IRA under the code, so it aggregates the same way. A wrinkle unique to SIMPLE plans is a 2-year seasoning period that starts when the first contribution lands. During those two years, rolling SIMPLE money into a 401(k) is barred, and an early distribution can trigger a 25 percent penalty rather than 10 percent. The balance still counts for pro-rata throughout.

Which accounts count vs. which are invisible to the pro-rata rule

The pro-rata rule sees only certain accounts. It aggregates every traditional-style IRA you personally own, yet it is blind to employer plans that are not IRAs and to Roth accounts. Knowing which balances land in the pool, and which do not, is the whole game when you decide whether a backdoor Roth is clean or costly. The table below sorts the common account types.

The pool: traditional, SEP, SIMPLE and rollover IRAs

Under IRC section 408(d)(2), all of your traditional, SEP, SIMPLE and rollover IRAs are treated as one single IRA for the taxable-amount calculation. You cannot cherry-pick which dollars convert. Even if your $7,500 nondeductible contribution sits in its own brand-new account, the IRS blends it with every other pre-tax IRA dollar you hold before deciding the taxable fraction.

What is excluded: 401(k), Solo 401(k), 403(b), 457(b), Roth (plus inherited and spousal IRAs)

Employer plans that are not IRAs stay invisible to the calculation. A 401(k), Solo 401(k), 403(b) or 457(b) balance does not enter the pool, which is exactly why the reverse-rollover fix works. Roth IRAs are excluded because they hold only after-tax money. An inherited IRA is not aggregated with your own IRAs, and a spouse’s IRAs never enter your calculation, because pro-rata is applied per individual.

Which date’s balance does the IRS use: December 31, not the conversion date

The pro-rata fraction uses your total IRA balance on December 31 of the conversion year, not the balance on the day you convert. This traps mid-year movers: someone who empties an IRA in March, converts in April, then rolls a SEP back in during November still has that balance counted on December 31. The timing that matters is year-end, a point worth confirming against the 2026 Roth conversion deadline.

How the tax is calculated on a SEP/SIMPLE owner’s backdoor Roth

The tax on a SEP or SIMPLE owner’s backdoor Roth turns on one fraction: how much of your total IRA money is after-tax basis versus pre-tax. When a large SEP or SIMPLE dwarfs a small nondeductible contribution, the after-tax slice is tiny, so nearly all of the conversion is taxed as ordinary income in the conversion year. Understanding the formula helps many savers estimate the bite before they convert.

The pro-rata formula

The tax-free percentage of any conversion equals your total after-tax basis divided by the total year-end (December 31) balance of all your traditional, SEP, SIMPLE and rollover IRAs combined. Everything left over is taxable ordinary income. The backdoor route matters because direct Roth contributions phase out between $153,000 and $168,000 of modified AGI for single filers, and between $242,000 and $252,000 for married couples filing jointly in 2026. Stated simply:

• Tax-free fraction = after-tax basis / total year-end IRA balance
• Taxable fraction = 1 minus the tax-free fraction
• Taxable income added = taxable fraction times the amount converted

Worked example: a freelancer with a $92,000 SEP

Consider an illustrative freelancer who holds $92,000 in a SEP IRA and makes a $7,500 nondeductible traditional IRA contribution to convert in 2026. The 2026 IRA contribution limit is $7,500, or $8,600 if you are age 50 or older, and this example uses the $7,500 figure. This is a hypothetical for education only and is not a projected result.

• Total year-end IRA balance: $92,000 plus $7,500 = $99,500
• After-tax basis: $7,500
• Tax-free fraction: 7,500 / 99,500 = about 7.5 percent
• Tax-free portion of the $7,500 conversion: about $565
• Taxable portion: about $6,935, roughly 92.5 percent of the conversion

So converting $7,500 that felt like after-tax money actually adds about $6,935 of ordinary income. At a 24 percent marginal rate that is roughly $1,664 of federal tax on a conversion the saver expected to be nearly tax-free. The leftover $6,935 of basis is not lost: it stays tracked on Form 8606 and reduces tax on future conversions, but the pro-rata blending repeats every year the SEP remains funded. Modeling this against your bracket, as covered in how much to convert to Roth, is often more useful than a rule of thumb.

Form 8606: reporting basis and the taxable fraction

Form 8606 is where the pro-rata calculation is documented. Nondeductible contributions are reported in Part I, which tracks your cumulative after-tax basis. The conversion and its taxable amount flow through Part II, where the pro-rata math produces the figure that lands on Form 1040 as taxable income. Filing Form 8606 in every year you make a nondeductible contribution is what preserves your basis; skipping it risks paying tax twice on the same dollars.

How the self-employed can empty the SEP or SIMPLE before December 31

Because the pool is measured on December 31, the self-employed have a fix most W-2 employees lack: moving pre-tax IRA money into a plan the rule cannot see. A Solo 401(k) is the usual vehicle. Completed before year-end, it can reduce the taxable fraction of a backdoor Roth toward zero, though the SIMPLE 2-year rule and setup deadlines constrain the timing.

The Solo 401(k) reverse rollover (establish and fund by December 31)

A Solo 401(k) (an owner-only 401(k)) is not an IRA, so any balance inside it is excluded from the pro-rata calculation. The reverse rollover moves your pre-tax SEP or traditional IRA dollars into the Solo 401(k). If the only IRA balance left on December 31 is the $7,500 of after-tax basis, the tax-free fraction approaches 100 percent. The plan must be established, not merely funded, and the rollover completed by December 31.

The SIMPLE IRA 2-year rule that can block the rollover

If your pre-tax money sits in a SIMPLE IRA, the 2-year clock can stop this plan cold. The clock starts on the date of the first contribution to your SIMPLE IRA. Before two years elapse, SIMPLE funds generally cannot be rolled into a 401(k), and a premature distribution can incur a 25 percent penalty on top of income tax. SEP IRAs carry no seasoning restriction, so a SEP can move to a Solo 401(k) immediately.

Alternatives if the reverse rollover isn’t available

When a Solo 401(k) rollover is off the table, other paths exist. One is to convert the SEP to a Roth over several years, accepting the tax to eliminate the pro-rata drag permanently, which pairs with modeling the Roth conversion break-even horizon. Another is simply to establish the Solo 401(k) before year-end so the window opens next year. Some savers instead pursue direct Roth conversions from the SEP and pay the tax deliberately.

When the backdoor Roth isn’t worth it

If the conversion is small relative to a large SEP and no Solo 401(k) fix is practical, the after-tax benefit of a $7,500 backdoor Roth may not justify triggering tax on the pro-rata slice each year. Some savers in that position pause the backdoor, focus on winding down the pre-tax balance, or defer. There is no single right answer; the outcome depends on your bracket, timeline and cash available to pay the tax.

Frequently asked questions

Does a SEP IRA count towards the pro-rata rule?

Yes. A SEP IRA is a traditional IRA under the tax code, so its pre-tax balance is aggregated with all your other non-Roth IRAs when the pro-rata rule computes the taxable portion of a Roth conversion. Even though it is employer-funded and feels like a workplace plan, the IRS blends it into the same pool as any traditional IRA under IRC section 408(d)(2).

Do SIMPLE IRAs count for the pro-rata rule?

Yes. A SIMPLE IRA is a traditional IRA under the code, so its balance counts in the pro-rata pool alongside your traditional, SEP and rollover IRAs. The SIMPLE 2-year seasoning rule does not exempt it; the money is aggregated the entire time. That rule only affects whether you can roll the SIMPLE balance out to a 401(k), not whether it counts on December 31.

How do I avoid the pro-rata rule with a SEP IRA?

The common fix is a reverse rollover: move the pre-tax SEP dollars into a Solo 401(k) or an employer 401(k) that accepts rollovers, since those plans are excluded from the pro-rata pool. If your only remaining IRA balance on December 31 is your after-tax basis, the conversion becomes nearly tax-free. The Solo 401(k) must be established and the rollover completed by December 31.

Does the pro-rata rule use the December 31 balance or the conversion date?

The pro-rata rule uses your combined IRA balance on December 31 of the conversion year, not the balance on the day you convert. Emptying an IRA before converting does not help if a SEP or rollover balance reappears by year-end. Because December 31 is the only snapshot that counts, mid-year moves are undone if the money returns to an IRA before then.

Can I roll a SEP IRA into a Solo 401(k)?

Yes. Pre-tax SEP IRA dollars can generally be rolled into a Solo 401(k), and SEP IRAs carry no seasoning restriction, so the rollover can happen right away. Removing the SEP balance from the IRA pool before December 31 shrinks the taxable fraction of a backdoor Roth. The Solo 401(k) must be established by year-end, not just funded, for the balances to fall outside the calculation.

Does a SEP IRA affect a backdoor Roth?

Yes, often significantly. Because a SEP IRA is aggregated with your nondeductible contribution, a large SEP makes most of a backdoor Roth taxable. In a $92,000 SEP plus $7,500 contribution example, roughly 92.5 percent of the conversion is taxable ordinary income. The backdoor Roth stays clean only if the pre-tax SEP money is moved out of the IRA pool before December 31.

What is the SIMPLE IRA 2-year rule?

The 2-year clock starts on the date of the first contribution to your SIMPLE IRA. Before it elapses, SIMPLE funds generally cannot be rolled into a 401(k) or Solo 401(k), and an early distribution can trigger a 25 percent penalty rather than the usual 10 percent. The SIMPLE balance still counts for pro-rata purposes throughout the seasoning period.