Medicare coverage starts based on when you sign up and which sign-up period you’re in.
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 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.” Learn more about how to avoid late enrollment penalties.
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 |
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.
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.
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.
Lost Medicaid coverage on or after 1/1/2023
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.
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.
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.
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. What happens if I choose a coverage start date 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*)
* If you have a disability, and your coverage is based on your (non-spouse) family member’s current employment, their employer must be in a large group health plan for you to be eligible for the Special Enrollment Period.
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 first month after you sign up. If you sign up for Part B while you're still working, or within the first full month after losing employer coverage, you can request to delay your Part B start date up to 3 months. This Special Enrollment Period doesn't apply if you're eligible for Medicare based on End-Stage Renal Disease (ESRD), or you're still in your Initial Enrollment Period.
COBRA isn't considered group health plan coverage.
Getting COBRA doesn’t change when this Special Enrollment Period ends.
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:
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.
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.
Situations that don’t qualify for a Special Enrollment Period:
Once you sign up for Medicare, you can join a health or drug plan at certain times. To join a Medicare Advantage Plan (Part C), you need both Part A and Part B. To join a Medicare drug plan (Part D) , you only need Part A or Part B. Find out when you can join a plan.