The number reported in Box 12 of Form W-2 - Wage and Tax Statement (code "W") is the amount your employer contributed to your health savings account (including cafeteria plan contributions). You'll need to enter this figure in your tax return.
To enter your Health Savings Account information in your tax return in TaxAct:
Note: The amount from Box 12 of Form W-2 will appear on the screen titled Enter Taxpayer's/Spouse's 2023 HSA contributions.
Note that any link in the information above is updated each year automatically and will take you to the most recent version of the webpage or document at the time it is accessed.