The backdoor Roth IRA, explained without the cloak and dagger

What is a backdoor Roth IRA?

A backdoor Roth IRA is not a special account. It is a nondeductible contribution to a traditional IRA, followed by a conversion of that money to a Roth IRA. It works because Roth contributions have income limits, but conversions do not. Done cleanly, little or no tax is due on the conversion.

Once the money is in the Roth IRA, it is treated like any other Roth money. Growth can come out tax free later, if you meet the rules for qualified distributions.

Who needs the backdoor in 2026?

Anyone whose income is above the Roth IRA limits. For 2026, the ability to contribute directly phases out between $153,000 and $168,000 of income for single filers and between $242,000 and $252,000 for married couples filing jointly. Above those ranges, the backdoor is the usual route.

The 2026 IRA contribution limit is $7,500, plus a $1,100 catch up for people age 50 and over, for a total of $8,600. You also need taxable compensation, such as wages or self employment income, at least equal to what you contribute.

The contribution for a given year can be made until the due date of that year's return, not including extensions. That gives you some breathing room into the spring.

What are the steps for a backdoor Roth IRA?

First, contribute to a traditional IRA and do not deduct it. Second, convert that IRA to your Roth IRA. Third, report both on Form 8606 with your tax return. Before you start, check whether you have any other pre tax IRA money, because that balance decides whether the conversion is tax free or partly taxable.

Many people convert soon after contributing so there is little or no growth in between. Any earnings before the conversion are taxable when converted, so waiting a long time adds a small tax bill.

One more thing: since 2018, a Roth conversion cannot be undone. There is no recharacterizing it back to a traditional IRA, so make sure the math works before you click convert.

What is the pro rata rule?

The pro rata rule treats all of your traditional, SEP and SIMPLE IRAs as one pot when you convert. You cannot convert only the after tax dollars. The taxable share of the conversion depends on how much of your total IRA balance is pre tax, measured using your December 31 balances for the year of the conversion.

Here is a simple example. Say you contribute $7,500 nondeductible and also have $92,500 in an old rollover IRA, all pre tax. Your total is $100,000, and only 7.5 percent of it is after tax money. Convert $7,500 and only about $562 of it is tax free. The other $6,938 or so is taxable. That is not a backdoor. That is a screen door.

The December 31 detail matters. Form 8606 uses the value of all your traditional, SEP and SIMPLE IRAs at the end of the year you convert. Rolling money into an IRA later that same year can make a conversion from January partly taxable after the fact.

The rule is per person. Your spouse's IRAs do not count against you, and each spouse who needs one files a separate Form 8606.

How can rolling a pre tax IRA into a 401(k) help?

Money inside a 401(k) is not counted in the pro rata math. If your employer plan accepts incoming rollovers, moving your pre tax IRA balance into it can bring your IRA balance down to just the after tax contribution. Only pre tax amounts can be rolled into the plan, which conveniently leaves the after tax basis behind.

Plans are allowed to accept these rollovers but are not required to, so check with the plan first. If you are self employed, your own Solo 401(k) can sometimes serve as the destination, if the plan documents allow it.

Timing matters here too. The rollover needs to be finished by December 31 of the year you convert, since that is the balance Form 8606 looks at.

What mistakes trip people up?

The common ones are forgetting about a SEP or rollover IRA, deducting the contribution by accident, skipping Form 8606, and converting without checking year end balances. Not filing a required Form 8606 for a nondeductible contribution carries a $50 penalty, and losing track of basis can mean paying tax twice on the same dollars.

Form 8606 is the record that proves your after tax basis. Keep a copy of every one you file. Years from now, it is the difference between a tax free withdrawal and an awkward conversation.

A backdoor Roth is easy to fold into year round tax planning, where the December 31 check happens before December 31. We work with business owners, real estate owners and families around Charlotte and virtually nationwide.

Next step

The December 31 balance check is easy to miss on your own. We fold it into year round tax planning so it happens before the deadline, not after. See our tax planning services, or book a free intro call to talk through your situation.