[Zeke]

You can defer Medicare if you're still employed. However, there is a time limit on applying after you quit, retire (or get fired and you're not sure about the next job). There is some paperwork involved. I know this because I was under my wife's work health ins until she retired. I was 70 when I first started Plan B. (Plan A is automatic no matter what at age 65.) All we had to do was have the former employer state that we were covered by the company plan until the date of termination and have them send a letter giving that exact date.

I can't tell you off hand how many weeks you have but don't miss it because late enrollment (unless differed as stated) carries a lifetime penalty expressed in %'s.