Understanding Medicare enrollment periods is critical. Each period allows different actions, and missing the correct window can result in delays, coverage gaps, or lifetime penalties.

1. Initial Enrollment Period (IEP)
Individuals first becoming eligible for Medicare (usually at age 65).

Timing: A 7-month window - 3 months before your 65th birthday month, your birthday month, and 3 months after.

What you can do: Enroll in Part A, Part B, Medicare Advantage, Part D, or apply for a Medicare Supplement (Medigap) Plan.

Important: Delaying Part B or Part D without creditable coverage may result in lifetime penalties.

2. General Enrollment Period (GEP)
Who it applies to: Individuals who missed their Initial Enrollment Period and do not qualify for a Special Enrollment Period.

Timing: January 1 – March 31 each year.

Coverage begins the month after enrollment.

Risks: Possible late enrollment penalties and coverage gaps.

3. Special Enrollment Period (SEP)
Triggered by qualifying life events.

Most common scenario: Working past age 65 with employer coverage. You receive an 8-month window to enroll in Part B after employment or coverage ends.

Other triggers include: Moving, losing employer coverage, gaining or losing Medicaid, qualifying for Extra Help (LIS), institutionalization, plan termination, or disaster situations.

4. Annual Enrollment Period (AEP)
Timing: October 15 – December 7 each year.

Coverage begins January 1.

You may switch between Original Medicare and Medicare Advantage, change Advantage plans, or change/add/drop Part D plans.

5. Medicare Advantage Open Enrollment Period (MA OEP)
Timing: January 1 – March 31 each year.

Who it applies to: Individuals already enrolled in Medicare Advantage.

You may switch to another Advantage plan or return to Original Medicare (and enroll in Part D).

Limit: One change permitted during this period.

6. Part D Initial Enrollment Period (Part D IEP)
Occurs at the same time as your Initial Enrollment Period at age 65.

Failure to enroll without creditable drug coverage may result in a lifetime late enrollment penalty.

7. Part D Special Enrollment Periods (Part D SEP)
Triggered by events such as moving, losing creditable drug coverage, gaining or losing Extra Help (LIS), or entering/leaving long-term care.

Most allow enrollment within 2 months of the qualifying event.

8. 5-Star Special Enrollment Period (5-Star SEP)
If a 5-Star rated plan is available in your area, you may switch once per year between December 8 and November 30.

9. Dual Eligible and Extra Help Special Enrollment Period (Dual/LIS SEP)
Individuals who qualify for Medicaid or Extra Help (LIS) may generally change plans once per calendar quarter during the first three quarters of the year.

Late Enrollment Penalties
Part B: 10% premium increase for each full 12-month period delayed without creditable coverage (typically for life).

Part D: 1% of the national base beneficiary premium for each month without creditable drug coverage (typically for life).

Lighthouse Medicare Solutions will provide proper guidance in order to avoid delays, coverage gaps, or lifetime penalties.