I have supplemental health insurance in addition to Medicare. Can I deduct the payments for 2018?

[1945aschrumpf]

on what line do I enter my supplemental health care premiums?

[Bsch4477]

You must itemize to deduct those premium expenses as a medical deduction and you can only deduct an amount that is greater than 7.5% of your AGI.  It would be unusual for someone covered by Medicare and supplemental insurance to have medical expenses that high but I have seen it happen.