You generally have to start signing up for Medicare when you first become eligible, which is usually at age 65. The key window is the 7-month Initial Enrollment Period: 3 months before the month you turn 65, the month you turn 65, and 3 months after that month.

What to know

  • Most people enroll in Part A and Part B when they’re first eligible, usually at 65.
  • If you already receive Social Security before 65, you may be enrolled automatically.
  • Some people can qualify earlier than 65 because of a disability, ALS, or End-Stage Renal Disease.
  • If you miss your first enrollment window, you may face delays and late enrollment penalties.

When you can wait

  • If you or your spouse still have active employer coverage, you may be able to delay Medicare without a penalty.
  • COBRA or retiree coverage usually does not let you delay in the same way.

Simple rule

If you’re turning 65 soon, start checking your Medicare timing about 3 months before your birthday so you don’t miss the sign-up window.

TL;DR

For most people, Medicare starts at 65, and you should sign up during the 7-month window around that birthday.