How do I see if I have pretax medical premiums?

[Critter]

Look at your Paycheck stub  or  ask the employer. 

[BMcCalpin]

If you are referring to pretax medical premiums paid through your employer, then on your W-2 in box 12 there will be a code DD with a dollar amount. This dollar amount is the sum of the pretax medical premiums that your employer paid and which you paid (it's all pretax).

Normally, when you enter this on the W-2 entry screen, you do not enter it any place else on the tax return.