Deductions & credits

Open your return in TurboTax and go back to the HSA interview (Deductions and Credits->Medical->1099-SA, HSA, MSA ** note wording may vary from product to product). Do the following:

In the box where the arrow is pointing, enter the amount that is missing from the code W ($1,200 from your description).

This will place the missing amount in your 8889 and apply it to your return. This will show up as Tax-free employer contributions in the HSA Summary at the end of the HSA interview.