Your Initial Enrollment Period
The window is 7 months long: the 3 months before your 65th birthday month, the birthday month itself, and the 3 months after.
Timing decides your start date. Sign up before your birthday month and Part B starts the month you turn 65. Sign up in your birthday month or later in the window and it starts the next month.
If you miss it
If you are covered by a current job (yours or your spouse’s), you can wait. You get a Special Enrollment Period that ends 8 months after the job or the coverage ends, whichever comes first.
Otherwise you wait for the General Enrollment Period, January 1 – March 31 each year, and coverage starts the month after you sign up. You may also owe the Part B penalty: 10% for each full year you went without it, for as long as you have Part B. The penalty calculator shows the cost.
| Period | When | Coverage starts |
|---|---|---|
| Initial Enrollment Period | 7 months around your 65th birthday month | Your birthday month, or the month after you sign up |
| Special Enrollment Period (job-based coverage) | Up to 8 months after the job or coverage ends | Depends on when you sign up |
| General Enrollment Period | January 1 – March 31 each year | The month after you sign up |
| Open Enrollment (plan changes) | October 15 – December 7 (2026 for 2027 coverage) | January 1, 2027 |
How to sign up
If you get Social Security benefits at least 4 months before you turn 65, you are signed up for Parts A and B automatically. Otherwise, sign up online with Social Security, or call Social Security at 1-800-772-1213.
Once you have Parts A and B, you choose the rest: a Medicare Advantage plan, or a Medigap policy plus a Part D drug plan. Your Medigap window opens when Part B starts. There’s no cost and no pressure, so book a free consultation and we’ll walk through it together.