Are Supplemental Medicare Health Insurance not deductible unless you are self employed?

I pay for Supplemental Medicare Insurance and cannot find where I can enter it.  In previous years I have entered it in my Medical Deductible Section, but see NO PLACE to enter it.  I am having a problem in that section to get the Doctor visit mileage number to enter the worksheet.  The box stays pink and the number will not enter and I cannot progress in the form process.