How a Backdoor Roth IRA Works

How a Backdoor Roth IRA Works—and the Tax Rule That Can Cause Problems
Roth IRAs offer an attractive combination of tax-free growth, potentially tax-free qualified withdrawals, and no required minimum distributions during the original owner’s lifetime.

However, higher-income households may earn too much to contribute directly to a Roth IRA. A strategy commonly called a “backdoor Roth IRA” may provide another way to fund one.

Despite its informal name, a backdoor Roth IRA is not a distinct type of retirement account. It is a two-step process that combines a nondeductible traditional IRA contribution with a subsequent Roth conversion.

The process can be relatively straightforward when it is implemented and reported correctly. The potential complication is the IRS pro-rata rule, which can cause an unexpectedly large portion of the conversion to become taxable.

How Roth IRAs Differ From Traditional IRAs
Contributions to a Roth IRA are made with after-tax dollars. The contribution does not generally produce a current-year tax deduction, but the account can grow without annual taxation.

Qualified Roth IRA withdrawals are also free from federal income tax. To be considered qualified, a distribution generally must satisfy the applicable five-year requirement and occur after age 59½, because of disability, following the owner’s death, or for another qualifying reason.

Traditional IRAs generally work differently. Depending on income and workplace-plan participation, a contribution may be deductible. Investment earnings grow tax-deferred, but taxable withdrawals are generally treated as ordinary income. Traditional IRA owners may also eventually be subject to required minimum distributions.

For high-income earners, the ability to build a source of potentially tax-free retirement income can make Roth assets an important part of a broader tax-diversification strategy.

Roth IRA Income Limits for 2026
Eligibility to contribute directly to a Roth IRA depends on modified adjusted gross income and tax-filing status.

For 2026, the ability to contribute directly begins to phase out at:

$153,000 for single filers and heads of household
$242,000 for married couples filing jointly

Direct Roth IRA eligibility is eliminated when modified adjusted gross income reaches $168,000 for single filers and heads of household or $252,000 for married couples filing jointly.

The 2026 IRA contribution limit is $7,500. Individuals age 50 or older may contribute an additional $1,100, bringing their potential total to $8,600.

These limits apply across a person’s combined traditional and Roth IRA contributions. They are not separate limits for each account.

High earners who cannot contribute directly may still be permitted to complete a Roth conversion because Roth conversions do not carry the same income restriction.

The Two Steps of a Backdoor Roth IRA
A backdoor Roth IRA generally involves two transactions.

Step 1: Make a Nondeductible Traditional IRA Contribution
The investor contributes after-tax money to a traditional IRA and does not claim a tax deduction for the contribution.

The nondeductible contribution creates after-tax basis in the IRA. This basis must be tracked and reported correctly to prevent the same dollars from being taxed again when they are distributed or converted.

Step 2: Convert the Funds to a Roth IRA
The investor then converts the traditional IRA assets into a Roth IRA.

If the contribution is converted before it generates meaningful investment earnings—and the investor has no other pre-tax IRA balances—the taxable amount may be minimal. Any earnings generated before the conversion will generally be taxable.

There is no rule requiring an investor to wait a specific number of days between the contribution and conversion. However, the timing and documentation should be reviewed with the investor’s tax professional.

Why the Pro-Rata Rule Matters
The most important potential complication is the pro-rata rule.

When determining the taxable portion of a Roth conversion, the IRS generally does not allow an investor to isolate only the after-tax dollars in one IRA. Instead, it looks at the investor’s combined balances across traditional, SEP, and SIMPLE IRAs.

The calculation considers:

The investor’s total after-tax IRA basis
The value of all traditional, SEP, and SIMPLE IRAs
Distributions and conversions completed during the year
The combined IRA balance on December 31

This means opening a new traditional IRA does not separate the new nondeductible contribution from pre-existing IRA assets.

A Pro-Rata Rule Example
Assume an investor has $95,000 in a traditional IRA containing entirely pre-tax assets. The investor then makes a $5,000 nondeductible contribution to another traditional IRA.

The investor now has:

$95,000 of pre-tax IRA assets
$5,000 of after-tax basis
$100,000 in combined IRA assets

Only 5% of the combined IRA assets represent after-tax basis.

If the investor converts $5,000 to a Roth IRA, approximately $250 of that conversion would be treated as a return of after-tax basis. The remaining $4,750 would generally be taxable as ordinary income.

The investor cannot simply identify the second IRA as the “after-tax account” and convert it tax-free. For this calculation, the IRS generally treats the investor’s applicable IRAs as one combined balance.

Employer Retirement Plans Are Treated Differently
Assets held in a 401(k), 403(b), or certain other employer-sponsored retirement plans are generally not included in the IRA pro-rata calculation.

In some situations, an employer plan may accept a rollover of pre-tax IRA assets. Moving eligible pre-tax IRA funds into an employer plan could reduce or eliminate the IRA balance subject to the pro-rata calculation.

That does not mean a rollover is automatically the right decision. Before moving assets, investors should compare:

Available investments
Plan expenses
Withdrawal flexibility
Creditor protection
Access to professional management
Whether the plan accepts incoming rollovers

The IRA’s after-tax basis generally should not be rolled into the employer plan. This is an area where careful coordination with the plan administrator, custodian, and tax adviser is particularly important.

Form 8606 and Tax Reporting
IRS Form 8606 is generally used to report nondeductible traditional IRA contributions, track after-tax basis, and calculate the taxable portion of Roth conversions.

Failing to file the form—or reporting the transaction incorrectly—can create complications years later. Without an accurate basis record, a taxpayer may have difficulty proving that part of a future conversion or withdrawal should not be taxed.

Investors should retain copies of all Forms 8606 and supporting IRA records as part of their permanent tax documentation.

Is a Backdoor Roth IRA Right for You?
A backdoor Roth IRA may be worth evaluating when:

Your income prevents a direct Roth IRA contribution
You have earned income that supports an IRA contribution
You have little or no pre-tax money in traditional, SEP, or SIMPLE IRAs
You have sufficient cash flow to make the contribution
Roth assets complement your long-term retirement and estate strategy
Your tax adviser can properly report and track the transaction

The strategy may be less attractive when a large existing IRA balance would cause most of the conversion to be taxable or when other retirement-planning priorities should come first.

The Bottom Line
A backdoor Roth IRA can give certain high-income earners access to the long-term benefits of a Roth account, but the strategy is not as simple as contributing money and immediately moving it between accounts.

Before proceeding, review every traditional, SEP, and SIMPLE IRA you own, understand the pro-rata calculation, and coordinate the transaction with your tax professional. Proper reporting is just as important as the investment decision itself.

At Tidecrest Wealth Management, we help families coordinate investment management, retirement planning, and tax-aware financial decisions within one integrated strategy.

If you would like to explore how Roth assets could fit into your long-term plan, we invite you to schedule a conversation with our team.

This material is provided for general educational purposes only and should not be considered individualized tax, legal, or investment advice. Tax rules and contribution limits may change. Consult qualified tax and financial professionals regarding your circumstances.