While doing '18,noticd I've excss contrib to HSA in '17.I checked the wrong box;single instd of family.Need to amend '17.Do I wait since '18 requires '17 5329's line 48?

[BMcCalpin · Accepted solution]

You are correct that you will need the line 48 number from the 2017 5329 to complete your 2018 return. If you e-file your 2018 now, you will just have to amend it later.

I suggest that you do the following in order to minimze your paperwork:

• amend your 2017 return now
• file an extension for your 2018 return
  
• without waiting for your 2017 amendment to be accepted by the IRS, e-file your 2018 return with the updated 2017 line 48 on the 5329
• write down what you did and why and stick it in your tax file

Note that even though you are requesting an extension, you actually don't have to wait 6 months to file - you can file your 2018 return at any time before October 15, 2019. I am suggesting the extension to give you some time to prepare the amended 2017 return (of course, you may not need it).

Note that this process means that there will be a period of time after your 2018 return is processed but before your 2017 amendment is processed (amendment processing is slower than original return processing) in which the data from the two years will conflict. However, comparisons across multiple years are usually not done by the IRS for a year, so it is very likely that before the IRS ever notices the conflict, your 2017 amended return will fix the conflict anyway.

But you have your notes in the very unlikely case that anyone ever writes you about this.

[ki]

Thanks a lot @TurboTaxBillMc ! It all makes sense except the last bullet point. Are you suggesting that I write it down for my own records so I won't forget, or that I write and attach to my 2018 return to file with IRS. If latter (file with IRS), is there are way to do so if I am e-filing with TurboTax? or are you suggesting that I print it out and send it in?

[BMcCalpin]

I am sorry that you thought the last bullet point was so confusing that you had to vote the answer as unhelpful. Perhaps the last bullet point should have read: "write down what you did and why and stick it in your tax file for your own records". I did allude to this when I wrote the last line: "But you have your notes in the very unlikely case that anyone ever writes you about this."

P.S. I also corrected the misspelling of "down" (was "done").