Last updated December 16, 2024
When does Medicare coverage start?
Initial Enrollment Period (IEP):
A seven-month period when a person can first enroll in Medicare (beginning three months before they turn 65, the month they turn 65, and the three months after they turn 65):
- Turning 65:
- Under 65 with a disability:
Enrollment time frames are different for people who become eligible because of end-stage renal disease or Lou Gehrig's Disease (ALS)
- What happens if your birthday is on the first of the month?
Your 7-month period starts earlier. It starts 4 months before you turn 65 and ends 2 months after the month you turn 65. Generally, your Medicare coverage starts the first day of the month before you turn 65.
General Enrollment Period (GEP):
- Usually occurs from January 1 - March 31
- Coverage begins the first day of the month after the person enrolls
- If a person missed their EIP and are not eligible for a Special Enrollment Period, they can enroll during the GEP. Late enrollment penalties may apply.
Special Enrollment Period (SEP) for Part A and Part B:
- Special circumstances may allow a person to enroll into Medicare Part A and Part B outside of their IEP, including:
- Individuals impacted by an emergency or natural disaster
- Group Health Plan (GHP) or employer misrepresentation
- Coordinate with termination of Medicaid coverage
- Employer insurance ending (see Medicare and employer insurance Quick Reference for more information)
- Formerly Incarcerated Individuals (see Medicare and incarceration Quick Reference for more information)
- Exceptional circumstances
- Helpful links:
Special Enrollment Period (SEP) for Part D or Advantage Plans:
- Special circumstances may allow a person to enroll in Medicare Part D or an Advantage Plan outside their IEP, including:
- moving out of their plan's service area
- losing employer-based coverage
- having Medicare Part D Extra Help.
- Helpful links:
Open Enrollment Period (OEP):
- Occurs annually from October 15 - December 7.
- Coverage begins January 1 of the following year.
- Change from Original Medicare to a Medicare health plan
- Change from a Medicare health plan to Original Medicare
- Join, drop, or switch Medicare Part D prescription drug plans
- Change to a different Medicare health plan
Note: there is NOT an open enrollment period for Medigap policies during this time.
Medicare Advantage Open Enrollment Period:
- New to Medicare: Those who enrolled in a Medicare Advantage Plan during their IEP can change to a different Medicare Advantage Plan or return to Original Medicare one-time only during the first three months of enrolling in Medicare Part and Part B.
- Annually: January 1 - March 31. A person enrolled in a Medicare Advantage Plan can switch to a different Medicare Advantage Plan or return to Original Medicare and enroll in a separate Part D plan.
When switching Medicare Advantage Plans, the person must not disenroll from their current plan. Enrolling in a new plan will trigger a disenrollment in the current plan.
Late enrollment penalties:
What are Medicare late enrollment penalties?
In most cases, if a person doesn't sign up for Medicare when first eligible, they may have to pay a higher monthly premium.
Late enrollment penalties:
- Are added to a person's monthly premium.
- Are not a one-time late fee.
- Are usually charged for as long as the person has that type of coverage (for most people, that’s a lifetime penalty). The Part A penalty is different.
- Go up the longer a person waits to sign up – they’re based on how long you go without coverage similar to Medicare. Find out when you should sign up to avoid penalties.
Medicare Part A:
Part A Late Enrollment Penalty (Medicare.gov)
Events that eliminate late enrollment penalty for Medicare Part A:
- Enrollment in Medical Assistance and/or Medicare Savings Program
- 65th birthday if on Medicare due to disability prior to that
- A person can pay twice the number of years they didn't sign up (i.e., if you were eligible for Part A for 2 years but didn't sign up, you'll have to pay the higher premium for 4 years. Usually, you don't have to pay a penalty if you meet certain conditions that allow you to sign up for Part A during a Special Enrollment Period.)
Medicare Part B:
Part B Late Enrollment Penalty (Medicare.gov)
Events that eliminate late enrollment penalty for Medicare Part B:
- Enrollment in Medical Assistance and/or Medicare Savings Program
- 65th birthday if on Medicare due to disability prior to that
Medicare Part D:
Part D Late Enrollment Penalty (Medicare.gov)
Medicare Rights Center - The Part D late enrollment penalty
Events that eliminate late enrollment penalty for Medicare Part D:
- Enrollment in Extra Help, Medical Assistance, and/or Medicare Savings Program
- 65th birthday if on Medicare due to disability prior to that
- Creditable prescription drug coverage including Veteran's prescription drug coverage, Indian Health Services, Postal Service Retirees
Reinstatement of Medicare Part B:
People requesting Part B reinstatement can request to be reinstated two ways:
1. Going forward - this means from the day they are requesting to reinstate their Medicare Part B coverage through the Social Security Administration.
2. Going back - this means from the day they lost their Medicare Part B coverage.
Note: Beneficiaries cannot pick and choose the months of reinstatement and they have to pay any back premiums in full before reinstatement is possible. There is no financial assistance to help pay for those previous missed Part B premiums.
Retroactive reinstatements are not always possible and are dictated by Social Security. Questions regarding Part B reinstatement should be directed to SSA.
Reminder about the Part B SEP: If you get Part B after your Part A coverage starts, you can join any Medicare Advantage Plan (with or without drug coverage) 3 months before your Part B starts until the last day of the month before your Part B starts. If you request to join a plan before your Medicare Part B starts, your plan coverage starts the same day as your Medicare Part B.
Medicare.gov | Understanding Medicare Advantage and Medicare prescription drug enrollment periods