No, you aren’t required to sign up for Medicare if you have private insurance. Your individual circumstances – including the nature of your health coverage — will determine whether this is the right decision for you.
However, if you have coverage through an employer with fewer than 20 employees, you should sign up for Original Medicare when you’re first eligible. In this situation, Medicare pays before your other coverage. If you delay enrolling, you may have to pay a lifetime penalty if you enroll later.
If you have individual coverage through a health care marketplace or directly from an insurer, you should sign up for Part A and Part B when you’re first eligible. Once your Medicare coverage begins, you should drop your individual plan coverage.