Medicare coverage starts based on when you sign up and which sign-up period you’re in.
Your first chance to sign up (Initial Enrollment Period)
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.
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.” Learn more about how to avoid late enrollment penalties.
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:
| If you sign up: | Coverage starts: |
|---|---|
| Before the month you turn 65 | The month you turn 65 |
| The month you turn 65, or during the 3 months after | The next month |
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.
NOTE about Health Savings Accounts (HSAs)
To avoid a tax penalty, you and your employer should stop contributing to your HSA at least 6 months before you apply for Medicare. This is because:
- If you’re 65 or older, your Part A coverage will start up to 6 months back from the date you sign up for Medicare or apply for benefits from Social Security (or the Railroad Retirement Board).
- You’re not eligible to make contributions to your HSA after you have Medicare.
If your Medicare Part A coverage overlaps when you made contributions, you’ll have to pay a tax penalty.
You can withdraw money from your HSA after your Medicare coverage starts to help pay your share of costs (like deductibles, premiums, coinsurance or copayments).
If you have a Health Savings Account (HSA) with a High Deductible Health Plan (HDHP) based on your or your spouse’s current employment, you may be eligible for a Special Enrollment Period to sign up for Part B without penalty.
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 the month after you sign up. 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)
After your first chance to sign up (Initial Enrollment Period), there are certain situations when you can sign up for Part B (and Premium-Part A) 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.
Special Enrollment Periods for Part A & Part B
| If you: | Your Special Enrollment Period: | How to sign up: |
|---|---|---|
| Lost Medicaid coverage on or after 1/1/2023
Download more information about your Medicare options if you lose Medicaid. [PDF, 469 KB] |
Starts: The day you’re notified that your Medicaid coverage is ending.
Ends: 6 months after your Medicaid coverage ends. Coverage begins: The month after you sign up, or the date your Medicaid coverage ends, whichever you choose. |
Fill out form CMS-10797 and send the completed form to your local Social Security office by fax or mail. |
| Missed a chance to sign up because you were impacted by a natural disaster or an emergency that’s declared or starts on or after 1/1/2023 (or if your authorized representative, legal guardian, or caregiver was impacted by a disaster or emergency) | Starts: The day the Federal, state or local government declares the emergency or disaster, or the date in that declaration (whichever is earlier).
Ends: 6 months after whichever of these happens later:
Coverage begins: The month after you sign up. |
Fill out form CMS-10797 and send the completed form to your local Social Security office by fax or mail. |
| Missed a chance to sign up because you got inaccurate or misleading information from your health plan or employer on or after 1/1/2023 | Starts: The day you notify the Social Security Administration that your health plan or employer misrepresented or gave you incorrect information.
Ends: 6 months later. Coverage begins: The month after you sign up. |
Fill out form CMS-10797 and send the completed form to your local Social Security office by fax or mail. |
| Were released from incarceration on or after 1/1/2023 (and missed a chance to sign up while you were incarcerated) | Starts: The day you’re released from custody.
Ends: The last day of the 12th month after the month you’re released. Coverage begins: The month after you sign up, or you can select retroactive coverage back to your release date (but not a date before your release date). You can only request retroactive coverage up to 6 months in the past. |
Fill out form CMS-10797 and send the completed form to your local Social Security office by fax or mail. |
| Missed a chance to sign up because you experienced other exceptional conditions
Note: You must contact Social Security to ask for this Special Enrollment Period |
Starts: Once you contact Social Security.
Ends: At least 6 months later. Coverage begins: The month after your sign up. |
Fill out form CMS-10797 and send the completed form to your local Social Security office by fax or mail. |
| Have or had health insurance through your job, your spouse’s job (or a family member’s job if you’re disabled) | Starts: The first month after your Initial Enrollment Period ends.
Ends: 8 months after the group health plan coverage or the employment ends, whichever happens first. Coverage begins: Generally the month after you sign up. In some situations you can choose to have your coverage start on the first day of any of the 3 following months. |
If you already have Part A, go to SSA.gov to sign up for Part B.
You can also send completed forms to your local Social Security office by fax or mail. Download forms: |
| Volunteer and serve in a foreign country | Starts: The first day of the month any of these happen:
Ends: 6 months later. Coverage begins: The month after you sign up. |
Go to SSA.gov to apply for Medicare online.
If you already have Part A, fill out form CMS 40B to sign up for Part B. Send the completed form to your local Social Security office by fax or mail. |
| Have TRICARE | Starts: When Social Security notifies you.
Ends: 12 months later. Coverage begins: The month after you sign up, or, you may decide for coverage to begin after the end of your Initial Enrollment Period. |
Get more information about how TRICARE works with Medicare. |
Check my specific situation to find out when to sign up.
Source: Medicare.gov