I contributed POST-tax paycheck dollars for a previous year HSA contribution. I contributed for tax year 2019, but in 2020 How do I benefit by making this contributions?

[minesh-bhula]

My company contribute money from my paycheck towards a previous year HSA contribution.
- I opened my HSA in 2020
- I made contributions for tax year 2019, but in year 2020
 
My dollars had to come out of my paycheck POST-tax because the company payroll taxes were already filed for 2019.

How does this impact my 2019 taxes as now I have made post-tax contributions to an HSA, so I didn't get the pre-tax benefits for these contributions. Moreover, is there a way for me to fill out my taxes so that I do receive a benefit for making these contributions?

[BillM223]

I am not sure I have a clear picture but it sounds like the company gave you money in 2020 to apply to your 2019 HSA, right?

If so, on your 2019 return, you said you have an HSA, and then on the screen that is headed "Let's enter [name]'s HSA contributions", add this amount to the second line for "personal" contributions. This will appear on line 12 of Schedule 1 (1040).

Make sure you tell the HSA custodian that the contributions are for 2019! And make the contributions TODAY!

I assume that this money will be added to your 2020 W-2 by your employer - you don't get to take the deduction if it wasn't taxed in the first place.