Medicare enrollment in Hawaii — periods & deadlines

Knowing when to enroll matters. Missing your Initial Enrollment Period can mean lifelong late penalties, while Annual Enrollment Period (October 15–December 7) is your chance to review and switch plans every year.

Initial Enrollment Period (IEP)

Your IEP is a 7-month window centered on your 65th birthday:

• 3 months before the month you turn 65
• The month you turn 65
• 3 months after the month you turn 65

If your birthday falls on the 1st of the month, your IEP shifts one month earlier. Enrolling before your birthday month means coverage starts on the 1st of your birthday month.

Annual Enrollment Period (AEP)

October 15 – December 7 every year. Changes take effect January 1. During AEP you can:

• Switch from Original Medicare to a Medicare Advantage plan, or vice versa
• Switch between Medicare Advantage plans
• Switch between Part D plans
• Add or drop Part D coverage

Medicare Advantage Open Enrollment Period (MA-OEP)

January 1 – March 31. If you're already in a Medicare Advantage plan, you can:

• Switch to a different Medicare Advantage plan
• Switch back to Original Medicare (and add a Part D plan)

You cannot use MA-OEP to switch from Original Medicare to Medicare Advantage.

Medigap Open Enrollment

Your one-time, 6-month Medigap Open Enrollment starts the month you turn 65 AND have Part B. During this window:

• Insurers must sell you any Medigap plan they offer
• They cannot deny coverage based on health
• They cannot charge more for pre-existing conditions

This is the best (and often only) time to buy Medigap without underwriting in Hawaii.

Special Enrollment Periods (SEPs) common in Hawaii

Disaster SEP

When a federal or state-level disaster is declared in Hawaii (hurricanes, volcanic eruptions, tsunamis, the 2023 Maui wildfires), affected residents get a Disaster SEP allowing Medicare changes outside standard windows. More on Hawaii disaster SEPs.

Moving to Hawaii (or between Hawaii islands)

If you move to Hawaii from the mainland — or your move within Hawaii takes you out of your plan's service area — you get an SEP to enroll in a Hawaii-based plan.

Loss of employer coverage

When you lose qualifying employer health coverage, you get an 8-month SEP to enroll in Part B without penalty.

Dual-eligible / D-SNP

Hawaii residents with both Medicare and Med-QUEST get quarterly SEPs (3 per year) to change Medicare plans, plus additional ones tied to Medicaid status changes.

Five-Star SEP

Once per year (December 8 – November 30), you can switch to a 5-star Medicare Advantage or Part D plan if one is available in your area.

Late enrollment penalties

• Part B penalty: 10% of the standard premium for every 12 months you delayed. Example: 2 years late = 20% extra forever.
• Part D penalty: 1% of the national base premium for each month you went without creditable drug coverage.
• Part A penalty (if not premium-free): 10% extra for twice the number of years you were eligible but not enrolled.

Hawaii enrollment tips

• Check inter-island plan service areas. A plan licensed for Honolulu County may not serve Kauai. Confirm before enrolling.
• If you split time between islands or with the mainland, Original Medicare with Medigap and a Part D plan offers the most flexibility.
• Sage PLUS offers free, unbiased enrollment help statewide. Call 1-888-875-9229.
• Don't auto-renew without reviewing. Plans change benefits, networks, and formularies every year. Always read your Annual Notice of Change (ANOC) sent each September.