How do amend 2020 tax return after making HSA contribution?

Was this a direct contribution to the HSA custodian? Note that this includes contributions made in 2021 for 2020. P.S., I hope you told the HSA custodian that it was for 2020!

Use this link for information on the general process to amend - this TurboTax FAQ.

Once you enter your return, do a Search (upper right) for hsa and click on the jump-to link (Mac users must find HSA in the Topics List). ***NOTE*** just type hsa and hit enter; don't click on any of the search terms being offered.

Go through the HSA interview and when you get to the screen that says "Let's enter [name]'s HSA contributions", enter this direct contribution (if that's what it is as opposed to something your employer told you about) on the second line as a personal contribution. Obviously, if you already have an amount there, add this new contribution to it.

Then, in the Review I think for amending, be sure to explain why you are amending. Making a contribution in 2021 for tax year 2020  is an OK reason, so long as you don't exceed the annual HSA contribution limit for 2020.

Make sense?