Generally, when you turn 65. This is called your Initial Enrollment Period. It lasts for 7 months, starting 3 months before you turn 65, and ending 3 months after the month you turn 65.
My Birthday is not on the first of the month.
Avoid the penalty
If you miss your 7-month Initial Enrollment Period, you may have to wait to sign up and pay a monthly late enrollment penalty for as long as you have Part B coverage. The penalty goes up the longer you wait. You may also have to pay a penalty if you have to pay a Part A premium, also called “Premium-Part A.”
When your coverage starts
The date your coverage starts depends on which month you sign up during your Initial Enrollment Period. Coverage always starts on the first of the month.
If you qualify for Premium-free Part A: Your Part A coverage starts the month you turn 65. (If your birthday is on the first of the month, coverage starts the month before you turn 65.)
Part B (and Premium-Part A): Coverage starts based on the month you sign up:
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If you sign up: |
Coverage starts: |
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Before the month you turn 65
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The month you turn 65
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The month you turn 65
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The next month
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1 month after you turn 65
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2 months after you sign up
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2 or 3 months after you turn 65
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3 months after you sign up
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Signing up for Premium-free Part A later
You can sign up for Part A any time after you turn 65. Your Part A coverage starts 6 months back from when you sign up or when you apply for benefits from Social Security (or the Railroad Retirement Board). Coverage can’t start earlier than the month you turned 65.
I have a Health Savings Account (HSA).
After your Initial Enrollment Period ends, you can only sign up for Part B and Premium-Part A during one of the other enrollment periods.
Between January 1-March 31 each year (General Enrollment Period)
You can sign up between January 1-March 31 each year. This is called the General Enrollment Period. Your coverage starts July 1. You might pay a monthly late enrollment penalty, if you don’t qualify for a Special Enrollment Period.
Get details about the late enrollment penalties.
Special Situations (Special Enrollment Period)
There are certain situations when you can sign up for Part B (and Premium-Part A) during a Special Enrollment Period without paying a late enrollment penalty. A Special Enrollment Period is only available for a limited time. If you don’t sign up during your Special Enrollment Period, you’ll have to wait for the next General Enrollment Period and you might have to pay a monthly late enrollment penalty.
Check my specific situation to find out when to sign up.
When coverage starts
Generally, coverage starts the month after you sign up.
Special situations include:
You have health insurance through a job and still working — You can sign up for Part A and Part B any time as long as:
- You have group health plan coverage.
- You or your spouse (or a family member if you’re disabled) is working for the employer that provides your health coverage.
- You also have 8 months to sign up after you or your spouse (or your family member if you’re disabled) stop working or you lose group health plan coverage (whichever happens first).
- Your 8-month Special Enrollment Period starts when you stop working, even if you choose
COBRA or other coverage that’s not Medicare.
You’re a volunteer, serving in a foreign country — Contact Social Security for more details.
Certain situations for people with TRICARE — Contact TRICARE for more details.
Situations that don’t qualify for a Special Enrollment Period:
- Your COBRA coverage or retiree coverage ends. If you miss your 8-month window when you stopped working, you’ll have to wait until the next General Enrollment Period to sign up.
- You have or lose your Marketplace coverage.
- You have End-Stage Renal Disease (ESRD). Learn more about Medicare coverage for ESRD.