Forgot to include form 8606 last year for Backdoor Roth. Timing with this years

[welliamwallace]

Last year I filed my taxes using IRS free fillable forms. Somehow I believe I forgot to include form 8606 for myself and my spouse to record our non-deductible IRA contributions, and conversions to Roth. However, the numbers on line 4a and 4b of the 1040 were correct.

• Can you confirm that My 2019 Tax Return Transcript would include "F8606" somewhere on it if I had indeed filed it? (It doesn't)
• Can I complete and mail in a correct form 8606 for 2019 for both myself and my spouse without a 1040-x? Form 8606 will have some portion of the Roth conversion taxable, but the numbers on line 4a and 4b of my original tax return were correct as if I filled out form 8606. Should I mail them separately or together?
  
• Do I need to sequence this in a certain way with filing my 2020 tax return, which will also include a form 8606?
• Instructions for form 8606 state " If you are required to file Form 8606 to report a nondeductible contribution to a traditional IRA for 2019, but don’t do so, you must pay a $50 penalty, unless you can show reasonable cause. " How and where do I pay this penalty?

[welliamwallace]

Update. I've found the IRS Internal Revenue Manuals Sec 21.6.5.4.1. I plan to send in these standalone form 8606 documents for 2019 which will include a "taxable amount" on line 18. That taxable amount was already included on my original form 1040 and therefore will not require any adjustments, but I'm not sure they will know that. Should I include a 1040X with no changes to be safe?

[secondcor521]

Just mail the two 2019 Form 8606s to the specified address.  They can be standalone forms; just sign yours at the bottom and have your spouse sign theirs at the bottom, and of course also make sure your name, SSN, and address are at the top of page 1.

You do not need to file a 1040X.  You can send yours and your spouses together.  I would not pay the $50 penalty ahead of time; if the IRS bills you for it (doubtful) then I would pay it then.

I would mail the 2019 Form 8606s now and then go ahead and file your 2020 Form 1040 with 2020's information on it, some of which of course may come from your 2019 Form 8606s.  I would not worry about waiting to make sure they receive the 2019 8606s first.