The number reported in box 12 of Form W-2 (Code W) is the amount your employer contributed to your health savings account (including cafeteria plan contributions). 

You will need to complete IRS Form 8889 Health Savings Account.

Steps

See Entering in Program - Form W-2

To enter the additional information for a health savings account for yourself and/or your spouse:

1. From within your TaxAct return (Online or Desktop) click Federal. On smaller devices, click in the upper left-hand corner, then select Federal.
2. Click Health Savings Accounts (HSA) in the Federal Quick Q&A Topics menu to expand the category, then click All HSA topics
3. The program will proceed with the interview questions for you to enter or review the appropriate information. The amount from box 12 of Form W-2 will appear on the screen titled Health Savings Accounts - Contributions.