The Tricky Terrain of Backdoor Roth IRAs: Three Common Mistakes

In the world of retirement planning, a backdoor Roth IRA is often touted as a useful strategy for high-income earners to save more tax-free money for their golden years. However, while this method can be highly beneficial, it also carries potential pitfalls that could lead to unnecessary tax complications and financial penalties. Below are three major mistakes taxpayers make with backdoor Roth IRAs.

1. Not Reporting Non-Deductible Contributions

A key step in the backdoor Roth IRA process involves making a non-deductible contribution to a Traditional IRA, then converting this to a Roth IRA. Many individuals overlook the essential task of reporting these non-deductible contributions on their tax returns. By IRS rules, non-deductible IRA contributions must be reported on Form 8606 when you file your taxes. This form helps to establish the basis in your Traditional IRA. If you neglect to file this form, the IRS has no way of knowing that your contributions have already been taxed. As a result, you could be double-taxed upon withdrawal.

2. Not Reporting the Basis in an IRA

Another common pitfall is failing to report the basis in an IRA. The basis is the total amount of after-tax contributions made to the account. This is crucial because, unlike earnings or pre-tax contributions, the basis is not subject to taxes or penalties upon withdrawal. Again, Form 8606 is the appropriate document to file with your tax return to avoid this pitfall.

3. Not Considering the Pro-Rata Rule

The third pitfall lies in neglecting to consider the pro-rata rule. This IRS rule stipulates that if you have any other Traditional IRAs (with pre-tax contributions or earnings), you must aggregate the value of all of them when calculating the tax on a conversion.

In other words, you cannot selectively convert only non-deductible contributions (the basis) to a Roth IRA and leave pre-tax contributions and earnings in your Traditional IRA. Instead, each conversion carries with it a proportionate amount of pre-tax and post-tax money, based on the total balance across all of your Traditional IRAs.


A backdoor Roth IRA can be a powerful tool for retirement savings, but it’s not without potential pitfalls. By ensuring that non-deductible contributions and the basis in your IRA are properly reported and by understanding and applying the pro-rata rule, you can avoid unnecessary tax implications and make the most of your retirement planning strategy.

Always consult with a tax advisor or financial planner before undertaking complex financial maneuvers like a backdoor Roth IRA. The benefits can be considerable, but understanding the rules is essential to prevent costly mistakes. For additional information on Roth contributions, distributions and taxation, please see IRS Publication 590b (

Submitted by: John Whitley