Retirement

Backdoor Roth IRA: how it works in 2026

If your income is too high to contribute to a Roth IRA directly, you can put money into a traditional IRA without deducting it and then convert it to a Roth. Conversions have no income limit. For 2026 that is up to $7,500, or $8,600 at 50 or older. The catch is the pro-rata rule: if you have other pre-tax IRA money, part of the conversion is taxable.

Who uses a backdoor Roth

A direct Roth IRA contribution phases out with income. A traditional IRA contribution has no income limit, and neither does converting a traditional IRA to a Roth. Doing the two in a row gets the money into a Roth by the side door.

Roth IRA income limits (modified AGI), from IRS Notice 2025-67. Above the top of the range, a direct contribution is not allowed.
Filing status	2026 phase-out range	Direct Roth contribution?
Single or head of household	$153,000 – $168,000	None above $168,000
Married filing jointly	$242,000 – $252,000	None above $252,000
Married filing separately (lived together)	$0 – $10,000	None above $10,000

The steps

The mechanics are simple. Most of the mistakes are in the paperwork.

Contribute to a traditional IRA and do not deduct it. For 2026 the limit is $7,500, plus $1,100 at 50 or older, and you need at least that much earned income (or a working spouse). You have until April 15, 2027 to contribute for 2026.
Convert it to a Roth IRA. The IRS allows a trustee-to-trustee transfer, a same-trustee transfer (often just a redesignation), or a 60-day rollover.
File Form 8606 with your return. Part I reports the nondeductible contribution, which becomes your basis. Part II reports the conversion and works out how much of it is taxable.
Expect a Form 1099-R from the IRA custodian for the conversion. It usually shows the full amount; Form 8606 is what shows that most or all of it is not taxable.

The pro-rata rule: why other IRAs matter

You cannot choose to convert only your after-tax dollars. Form 8606 adds up the value of all your traditional IRAs, which includes SEP and SIMPLE IRAs, on December 31 of the year of the conversion, and treats each dollar converted as a mix of after-tax and pre-tax money in that proportion. Balances in a 401(k) or 403(b) are not part of this calculation.

Worked example using the Form 8606 line 6–10 arithmetic. You contribute $7,500 nondeductible and convert $7,500 in the same year. Earnings are ignored.
	No other IRA money	$92,500 in an old rollover IRA
After-tax basis	$7,500	$7,500
Traditional IRA value on Dec 31, plus the conversion	$7,500	$100,000
Share that is tax-free	100%	7.5%
Tax-free part of the $7,500 conversion	$7,500	About $563
Taxable part	$0	About $6,937

Getting around the pro-rata rule

The usual fix is to move the pre-tax IRA money out of the IRA calculation before December 31.

Roll pre-tax IRA money into your employer’s 401(k), if the plan accepts incoming rollovers. Only the pre-tax part can go in; the after-tax basis stays behind.
Convert everything and pay the tax this year, if the balance is small or your income is unusually low this year.
Watch SEP and SIMPLE IRAs. Self-employed people often forget these count as traditional IRAs for this rule.
The date that counts is December 31 of the year you convert, not the day you convert. A rollover IRA opened later in the same year still gets counted.

Taxes, timing and the 5-year rule

A few rules decide whether a backdoor Roth costs you anything.

Earnings between the contribution and the conversion are taxable when converted. Many people convert soon after contributing so there is little or nothing to tax.
A conversion cannot be undone. Since 2018 a Roth conversion cannot be recharacterized back to a traditional IRA.
Each conversion has its own 5-year clock for the 10% early-withdrawal tax if you are under 59½. It applies only to the part of the conversion that was taxable, so a clean backdoor with no pre-tax money has little exposure.
When you take money out of a Roth, regular contributions come out first, then conversions (oldest first, taxable part first), then earnings.
Penalties for paperwork: $50 for not filing a required Form 8606 and $100 for overstating nondeductible contributions, unless you show reasonable cause.

Married couples

Each spouse has their own IRA and their own pro-rata calculation. A spouse with no earned income can still do a backdoor Roth through a spousal IRA if you file jointly and your combined earned income covers both contributions. One spouse’s old rollover IRA does not affect the other spouse’s conversion.

The mega backdoor Roth

This one happens inside a 401(k), and only if the plan allows it. For 2026 the total that can go into your 401(k) account from all sources is $72,000 (plus catch-up). Some plans let you add after-tax (not Roth) contributions on top of your $24,500 deferral and the employer match, and then convert them to Roth, either inside the plan or by withdrawing them to a Roth IRA.

Example: under 50, $24,500 of deferrals and $7,500 of employer contributions leaves room for up to $40,000 of after-tax contributions, if the plan permits them.
You need both features: after-tax contributions and a way to convert them (in-plan Roth conversion or in-service withdrawal). Check your plan’s summary plan description.
Earnings on after-tax money before it is converted are taxable, so frequent or automatic conversion helps.
Plan nondiscrimination testing can limit after-tax contributions for higher earners. Your plan administrator can tell you your cap.

Is the backdoor Roth allowed?

Each step is allowed on its own: nondeductible IRA contributions have no income limit, and conversions have had no income limit since 2010. The IRS has not issued a rule that names the backdoor Roth. If you have a large pre-tax IRA balance, or a business with a SEP, get the numbers checked before you convert.

Get your backdoor Roth done right

USTAXX checks your IRA balances for the pro-rata rule and files Form 8606 with your return, including late 8606s for past years. In Naperville, IL, or remotely.

Tax consulting and planning Book a consultation (847) 773-7070

Questions people ask

What is the backdoor Roth limit for 2026?

The same as the IRA limit: $7,500, or $8,600 if you are 50 or older. It is shared with any other traditional or Roth IRA contributions you make for 2026.

Does my 401(k) count for the pro-rata rule?

No. Form 8606 counts traditional, SEP and SIMPLE IRAs only. Rolling pre-tax IRA money into a 401(k) is the common way to clear the way for a backdoor Roth.

Do I owe tax on a backdoor Roth?

If you have no other pre-tax IRA money, only on any earnings before the conversion, which is usually a few dollars. If you do, part of the conversion is taxable under the pro-rata rule.

What if I forgot to file Form 8606?

File it late, by itself or with an amended return. Without it, the IRS has no record of your basis and may treat the whole conversion as taxable. The penalty for not filing is $50 unless you show reasonable cause.

Can I do a backdoor Roth for 2026 in 2027?

Yes. You can make the 2026 nondeductible contribution until April 15, 2027. The conversion is taxed in the year you do it, so a conversion in 2027 goes on your 2027 Form 8606.

Where these rules come from

General information, current when written, not advice about your situation. Fees and forms change; the official pages above are the authority.