I get this question quite a bit:  If I am still working do I have to enroll in Medicare?  The rule of thumb is that as long as you have creditable group health coverage with an employer with over 20 employees, then you can postpone enrolling in Medicare until you are ready to retire.

Medicare.gov has some good info out there, this specific page is:  https://www.medicare.gov/basics/get-started-with-medicare/medicare-basics/working-past-65

**NOTE:  That is of course the easy answer, however you should compare what you are paying for group health and the benefits with  Medicare a/b and supplemental coverage to see what works best for you.