My wife has never worked. When I go on Medicare do I pay her Medicare cost?

If your wife is a citizen of at least five years and is 65 years old, she does qualify for Medicare coverage. It won't be free, of course. She will need to pay the premiums for the selections that she makes. It may not be deducted from you SS check, but could be billed directly to her. If that is the case you'll have to arrange for the monthly premiums to be paid. Hope this helps relieve your mind some.

medicaredotgov has an eligibilty calculator for you

You would need to check with Medicare regarding your wife since she has never paid into Medicare through employment. I know she cannot be on your Medicare insurance as that is for you alone.

Another option, check and see if she would quality for Medicaid, otherwise you would need to purchase a separate health insurance for her. For separate health insurance you could go onto HealthCare.gov and see what is available.

How old is your wife and how long have you been married? When you start drawing Social Security, your wife will also be able to get Social Security based on your work record if you have been married long enough and she is old enough. Everyone who qualifies for Medicare Part A gets it without charge. I assume that you are asking about Part B. Part B is deducted from your Social Security check, but if you are not yet drawing Social Security, you can pay it directly. I think that it is billed quarterly.