If you were eligible to be claimed as a dependent in 2017, then you were not eligible to make any contributions to an HSA. There are a number of steps you will have to take.
1. Contact the HSA administrator and ask for the withdrawal of a
"Mistaken Contribution". Be nice because they don't have to
accommodate you (explain about the employer making contributions when you weren't
eligible). If they honor this request, then they will send you a check for the
total amount contributed.
2. If
you took any distributions from the HSA (i.e., paid for medical expenses using
the debit card from the HSA administrator), contact your HSA administrator and
report a "Mistaken Distribution". This is the amount that you took
out of the HSA to pay for medical expenses. Again, be nice. They will ask you
to complete a form and to send it to them along with a check for that amount.
3. When
you enter your data in TurboTax, report your original numbers (like the amount
with code W in box 12 of your W-2). Then indicate that you had "none"
for HDHP coverage all year (yes, of course you did, but you weren't eligible
for the HSA). This will cause TurboTax to declare all contributions as excess
contributions. TurboTax will then ask if you will withdraw the entire excess
before the due date of the return. Since you are already working on this
(see #1), you answer "yes", and the contributions will be added to
line 21 (Other Income) as they should be (if the contributions were from your
W-2, otherwise, the amount that is excess won't be added to line 25 of the
1040).
4. Next year (i.e., for tax return
2018), you will probably get a 1099-SA reporting earnings on excess
contributions. You will enter that in the HSA interview and be taxed on it (as
is right).
