The word is out. The Backdoor Roth IRA is a powerful tax planning tool. You may believe that by previously executing Backdoor Roth IRAs, you have planned well and received a great tax benefit while building retirement savings.

Is it possible you are mistaken? It is possible you did not complete the Backdoor Roth IRA correctly? 

It may be true that you have successfully completed the two independent steps of a Backdoor Roth IRA: a traditional, non-deductible IRA contribution followed by a later Roth IRA conversion. It may also be true that you had no balances in a traditional IRA, SEP IRA, and/or SIMPLE IRA as of December 31st of the year you did the Backdoor Roth IRA. 

Year-end tip: The deadline to clean out traditional/SEP/SIMPLE IRAs (by rolling them into employer retirement plans such as 401(k)s) so as to optimize a Backdoor Roth IRA is December 31st of the year of the Roth IRA conversion step. As a practical matter, you should not complete the Roth IRA conversion step until you have cleaned out the traditional/SEP/SIMPLE IRAs. Life happens; there is simply no guarantee you complete the clean out before December 31st. Failing to do so will significantly increase the tax on your Backdoor Roth IRA. 

But you may not have correctly reported the Backdoor Roth IRA on your tax return. This last step is too-often overlooked. Below I discuss how to properly report a Backdoor Roth IRA, a potential tax return mistake that could have cost you thousands in erroneous taxes, and ways to fix the mistake. 

Backdoor Roth IRA Example

Charlie is single and 35 years old. He is covered by a retirement plan at work. In 2018 his W-2 salary was $200,000, and thus he did not qualify to make a Roth IRA contribution for 2018. He has no balance in a traditional IRA, SEP IRA, or SIMPLE IRA. He decides to do a Backdoor Roth IRA. 

On September 2, 2018, Charlie contributed $5,500 to a traditional, non-deductible IRA. On October 10, 2018, he converted the entire balance in the traditional IRA, then $5,510, to a Roth IRA. 

So far, so good with the Backdoor Roth IRA! But Charlie’s not done yet. Let’s look at how the Charlie should file his tax return and the pitfalls he should avoid.

Backdoor Roth IRA Tax Return Reporting

Early in the year, Charlie should receive a Form 1099-R that looks like the following from his financial institution.

This requires precise tax return reporting to ensure Charlie increases his taxable income by the correct amount to account for the Backdoor Roth IRA. An error in the tax return reporting could erroneously overstate his adjusted gross income and thus cause him to pay significantly more to the IRS and state tax agency than he owes.

There are two places Charlie needs to report the Backdoor Roth IRA: Pages 1 and 2 of Form 8606 and lines 4a and 4b of the Form 1040.

Let’s start with the Form 8606. Below is the correct way for Charlie to file Page 1 of his Form 8606.

Notice a few things about this form. First, on line 1 Charlie reports his traditional, non-deductible IRA contribution of $5,500. Second, on line 6, Charlie reports the total combined value of his traditional IRAs, SEP IRAs, and SIMPLE IRAs as of December 31, 2018. He can find this number on the Forms 5498 that his financial institutions send him and the IRS regarding his IRA accounts. To have a very efficient Backdoor Roth IRA, ideally Charlie should no balance in these accounts on December 31, 2018, and thus Charlie can, and does, report zero on line 6. If Charlie has any such balances the total must be reported here and it will cause his Backdoor Roth IRA to be partially (maybe mostly) taxable. 

Next, Charlie reports his Roth IRA conversion amount on line 8. This is the total taxable amount he converted, reported to him in Box 2 of the Form 1099-R, $5,510. The mechanics of the Form 8606 then lead to lines 11 and 13, the nontaxable portion of Charlie’s Roth IRA conversion. In Charlie’s case, this is $5,500. This is because he is entitled to recover all $5,500 of basis he has in his traditional IRA (as computed in this part of the Form 8606). This $5,500 number is required to correctly prepare Page 2 of the Form 8606 and line 4b of the Form 1040.

Page 1 computed how much of Charlie’s basis he can recover and the nontaxable portion of his Roth IRA conversion. Page 2 answers the second question: How much of Charlie’s Roth IRA conversion is taxable? Line 16 is simply line 8, and line 17 is simply line 11. Subtracting the nontaxable portion of the Roth IRA conversion from the total converted amount yields the amount of the Roth IRA conversion that is taxable. In Charlie’s case, it is only $10. This amount goes to Charlie’s Form 1040, line 4b. 

The Wrong Way

The following is what Charlie’s Form 1040 might look like if his Backdoor Roth IRA is misreported. 

How might this happen? It could be that a Form 8606 simply was not prepared, or it was incorrectly prepared. Sometimes the Form 1099-R is misunderstood. People see that $5,510 is the “taxable amount” in line 2 of the Form 1099-R and believe that must be the taxable amount reported on line 4b. But remember, the Form 1099-R has a box checked indicating that the taxable amount is not determined. The Form 8606 is what determines the taxable amount created by the Backdoor Roth IRA (in Charlie’s case, $10). 

As a check, you should ensure that the Lines 18 of your previously filed Forms 8606 agree to the appropriate line on the Form 1040 (line 4b in 2018). If there are discrepancies (and/or a Form 8606 was not filed for a Backdoor Roth IRA), that is an indication there is likely an error on the tax return. If Line 18 on the Form 8606 is a four-figure or greater number after a Backdoor Roth IRA, it is very likely that either the tax planning or the tax return reporting went wrong somewhere.

We can see how deleterious this error is for Charlie. If he filed his tax return the wrong way, his federal taxable income is overstated by $5,500. In his case, this caused him to erroneously owe $1,760 more in federal income tax ($43,613 minus $41,853 — hat tip to ProConnect Tax Online for the tax calculations). If Charlie lives in a state with a state income tax, he will also overpay his state income taxes because of this error. 

Filing an Amended Tax Return

Imagine that Charlie filed his tax return as pictured in the Wrong!!! picture above. What can Charlie do?

Charlie’s remedy is to file an amended return. This entails refiling the Form 1040 and all of its related forms and schedules (including the Form 8606) with the correct amounts. It also entails filing a Form 1040X. This form presents amounts as originally filed and as corrected, with the difference illustrated. It also requires a narrative submission explaining the changes made on the amended tax return.

There are several things to keep in mind when filing an amended tax return. First, a taxpayer filing an amended return is under an obligation to correctly report amounts. If, as part of the exercise of fixing a Backdoor Roth IRA through an amended tax return, the taxpayer learns that other amounts on the originally filed tax return were incorrect, he or she must correct those amounts if they choose to file an amended return. 

Second, there is a deadline for amending a federal income tax return (the so-called statute of limitations). Generally, the deadline is three years from the later of the tax return due date (if originally filed on or prior to the initial tax return due date) or the filing date (if filed after the initial tax return due date). This later deadline applies anytime the taxpayer files after the initial due date (including, for example, a timely post-April 15th tax return filing made after filing for an extension). 

If the amended return claiming the refund (because of the corrected Backdoor Roth IRA tax return reporting) is filed after this three year deadline, the IRS cannot and will not issue a refund to the taxpayer due to the statute of limitations. There are limited exceptions to this rule (such as when the IRS and the taxpayer have mutually agreed to extend the statute of limitations). 

States have their own statutes of limitations, which may or may not be the same as the federal statute of limitations. In my home state of California, it is a four-year statute of limitations instead of a three-year statute of limitations. 

The statute of limitations means the clock is ticking to correct Backdoor Roth IRAs not correctly reported on previously filed tax returns. In many cases, taxpayers learning they have incorrectly filed a tax return (for whatever reason, including an erroneously reported Backdoor Roth IRA) are well advised to seek professional assistance in amending their tax returns. 

Further Reading

I have previously blogged about Backdoor Roth IRAs for beginners here and about tactics to employ if you want to do a Backdoor Roth IRA but currently have a balance in a traditional IRA, SEP IRA, and/or SIMPLE IRA.

FI Tax Guy can be your financial planner! Find out more by visiting mullaneyfinancial.com

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This post is for entertainment and educational purposes only. It does not constitute accounting, financial, investment, legal, or tax advice. Please consult with your advisor(s) regarding your personal accounting, financial, investment, legal, and tax matters. Please also refer to the Disclaimer & Warning section found here.