What is a Backdoor Roth Conversion?

Matt Gray, CFP®
Most terms in the world of personal finance muddy the waters far more than they provide clarification. One of these terms is the Backdoor Roth Conversion which is often confused with the simpler Roth Conversion. Both can be useful strategies depending on your situation, but backdoor Roth conversions are a little bit more complex due to the potential pitfalls involved.

Recent tax proposals were potentially going to eliminate this strategy, but it appears now that it will continue to be permitted going forward. Continue to mind the potential upcoming tax changes and discuss them with an advisor before making any changes to your situation.
Is a backdoor Roth conversion appropriate for you? Should you complete a backdoor Roth conversion? What are some common mistakes when completing one? Let's take a deeper look at the details below.

Backdoor Roth Conversion Vs. Roth Conversion

We very frequently see confusion around these two common strategies, which is understandable because they are similarly named and involve similar movements. That said, they can apply to vastly different people and situations.

A Roth conversion refers to transferring money from a Traditional IRA to a Roth IRA. The catch with Traditional IRAs is that you usually have to pay income tax on the dollars you take out, and this includes dollars that move to a Roth IRA. So, in completing a Roth conversion, you are electing to pay taxes NOW instead of later on (usually in retirement) when you would take the money out. The benefit of this strategy is that the dollars that are now in the Roth grow tax-free forever. It does not apply well to everyone, and you should talk to a financial advisor to see if it matches your needs.

The backdoor Roth conversion is a more complicated strategy. It involves making a special type of contribution to a Traditional IRA called a non-deductible contribution and then quickly converting those dollars into a Roth IRA. You can see both strategies involve moving money from a Traditional IRA to a Roth IRA, which is why both include the idea of a "Roth Conversion," but the backdoor is a bit of a "loophole" in the tax code.

Why Not Just Put Money Into A Roth?

The sensible question when beginning to understand this strategy is why someone wouldn't simply put the money in the Roth IRA to start? Why does anyone need to create more steps by putting it into the Traditional IRA first?

The tax code currently has a provision involving retirement accounts called a "phase-out limit." This limit states that if you make over a certain amount of money (and a few other factors), you are not allowed to put money into the Roth IRA. Anyone is allowed complete a Roth conversion, but not everyone can put money directly into a Roth IRA. This is the exact provision that the backdoor Roth conversion is circumnavigating.

The Catch With Traditional IRA Contributions

Putting money into an IRA gives many people a tax deduction which lowers their tax bill. This is not the case for everyone because the IRS takes that away for people who make over a certain amount of money (another type of phase-out limit). The amount changes most years and depends on various factors, including how you file your taxes. If you qualify for the deduction when you put money in an IRA, a backdoor Roth conversion is probably not an ideal strategy for you as you likely want to take the tax deduction you get for putting money in the IRA.

For those with higher incomes and who can't take the tax deduction, you can elect to make a "non-deductible contribution." This means you put money in an IRA, but you don't get a tax break. Talk to your accountant or financial advisor about this, as you have to file a special tax form to notify the IRS you did this. When you make a non-deductible contribution, you can then move that money into a Roth IRA without paying taxes on it.

One More Catch: The Pro Rata Rule

As with many financial things, multiple pitfalls can unravel an entire strategy when not executed properly. The Pro Rate Rule is another example of this and is a little bit confusing to follow.

If you have an existing IRA with pre-tax dollars (old 401K money, contributions you received a tax deduction for, etc.), then make non-deductible contributions (as explained above), you must understand the proportion of each before converting to a Roth IRA. This is because the IRS does not allow you to cherry-pick the exact non-deductible dollars to convert tax-free. They want all Traditional IRA dollars to be considered when determining if and how much you owe in taxes. Look at the example below:

Pre-Tax IRA (let's say it was an old 401K) - $95,000, Non-Deductible Contribution - $5,000, Total Value - $100,000

You want to convert the $5,000 from the IRA into your Roth IRA and do so tax-free. Unfortunately, 95% of the account is pre-tax, and only 5% is after-tax (non-deductible). If this were the case, then you would be taxed on 95% of the $5,000 you convert to the Roth IRA, or $4,750 would be taxed as income ($5,000 X .95). You are not allowed to pick the $5,000 of non-deductible dollars, you must take a proportional amount of each bucket; deductible and non-deductible.

Final Thoughts

As you can see, this moderately complex strategy has a lot of what-ifs and potential pitfalls if not executed properly. For those it does work for, it is a strong strategy to get money into a Roth IRA and grow tax-free. Here are some common characteristics for whom this strategy may work best for:

  • High earning households making too much to get tax deduction for IRA contributions
  • No existing IRAs or very small existing IRAs
  • Typically, the younger, the better (it still can work for those later in their careers)
  • Already maxing out retirement plan(s) through their employer

Always consult an advisor before making complex financial moves and to see if a given strategy is in your best interest.

About the Author - Matt Gray is a Childfree Financial Planner who holds both the Certified Financial Planner® designation and the Chartered Advisor of Philanthropy designation. He enjoys working with his Childfree peers because he enjoys helping solve the specific needs of the Childfree community. Furthermore, he believes choosing a less traditional life path leads to more unique life stories and he loves helping those stories become a reality.