The IRS requires you to file form 8889 (for the Health Savings Account) if you:
- made a contribution in 2016,
- took a distribution in 2016, or
- inherited the HSA during 2016
If none of these apply, then you do not need to file the 8889 for 2016.
But if there is a code "W" in box 12 on your W-2, then you or your employer made contributions to your HSA, and reporting the HSA on form 8889 is required.
And if you received a 1099-SA, that means that you used funds from the HSA and are required to file the form 8889.
If you have contributions to the HSA or distributions from the HSA and you do not have the 8889 on your return, then your contributions and/or distributions are considered taxable.
In this case, expect a letter from the IRS asking you to send the form and possibly being assessed additional taxes, penalties, and interest.