Are personal contributions I make to my HSA reflected on the 1099-SA I get?

What if I made an HSA contribution that wasn't reported on my W-2?

We'll ask about this uncommon situation when you step through the Medical section. Look for the questions Did you put money into an HSA in 2021? or Do you need to make any adjustments to your HSA contribution amount? When you answer Yes, we'll open a screen where you can enter your contribution.

In most cases, your HSA contribution is reported in box 12 of your W-2 with the code W (Company Contributions to Health Savings Account).

Tip: Code W actually reports the combined contribution – yours plus your employer's. So if you contributed $1,500 to your HSA and your employer matched it dollar for dollar, box 12 on your W-2 would show $3,000 with a code W.

The 1099-SA only reports withdrawals (distributions). 

Money you contribute via payroll contribution (including employer funds) is reported on your W-2 in box 12 with code W.  You do not report those contributions again.

Money you contribute out of pocket will be reported by the HSA bank on form 5498-SA, but this form is usually not issued until May.  If you made out of pocket contributions, report the amount based on your own records, or get your record of deposits from the bank.  You don't need to wait for the form 5498-SA.