Working past 65 in Hawaii — Medicare and employer coverage

Hawaii's high cost of living means many residents work well past age 65. The interaction between Medicare and employer health coverage is one of the most consequential — and most misunderstood — decisions for Hawaii's working older adults.

The basic question: enroll in Medicare or delay?

If you're approaching 65 and still working with employer health coverage, you have three main paths:

1. Enroll in Medicare (Parts A and B) and use it alongside or instead of employer coverage
2. Enroll only in Medicare Part A (free for most) and delay Part B
3. Delay Medicare entirely (rare; only viable in specific employer-coverage situations)

Which is right depends on your employer's size, the quality of your employer coverage, and your personal health and finances.

The "20 employee" rule — the most important factor

Federal law treats large and small employer health plans differently when Medicare is involved:

Employer size	Who pays first?
20 or more employees	Employer plan pays first; Medicare second
Fewer than 20 employees	Medicare pays first; employer plan second

This matters because:

• If your employer has 20+ employees — you can typically delay Medicare Part B without penalty while keeping employer coverage. Sign up for Medicare during a Special Enrollment Period when you retire.
• If your employer has fewer than 20 employees — you generally need to enroll in Part B at 65 because your employer plan won't pay primary. Delaying Part B can mean serious gaps in coverage.

Always confirm your employer's status with HR — and ideally get it in writing before relying on it.

Special situations

Should you enroll in Part A even while working?

Part A is free for most workers (those with 40+ quarters of Medicare-taxed work history). Many people who delay Part B still enroll in Part A at 65. Pros and cons:

• Pro: Part A as secondary insurance can help with hospital costs not fully covered by employer plan
• Con: Enrolling in Part A makes you ineligible to contribute to an HSA

If you have an HSA and want to keep contributing, delay Part A enrollment until you stop working or stop using the HSA-qualified plan. Otherwise, Part A enrollment is generally a good idea.

Special Enrollment Period when you eventually retire

When you stop working (or your employer coverage ends), you get a Special Enrollment Period to sign up for Medicare:

• The SEP starts the month after employment ends or coverage ends, whichever is first
• The SEP lasts 8 months
• You can enroll in Part B without late penalty
• You also get a 2-month SEP for Medicare Advantage and Part D

Don't miss this window — outside of it, you're stuck with the General Enrollment Period (January-March) and possible coverage gaps.

Hawaii-specific situations

• Federal employees and Pearl Harbor shipyard workers — see our FEHB guide
• State and county workers (EUTF) — see our EUTF guide; Part B is required when you actually retire
• University of Hawaii employees — UH retirees use EUTF; same rules apply
• Hospitality workers — many union plans qualify as 20+ employee coverage
• Self-employed — generally treated as fewer than 20 employees; enroll in Medicare at 65
• Working multiple part-time jobs — depends on each employer's size

Practical advice

1. Talk to HR 6+ months before turning 65 — confirm employer size and Medicare coordination rules in writing
2. Apply for Medicare Part A at 65 if you don't have an HSA-qualified plan
3. Make a clear decision about Part B — based on the 20-employee rule and your specific coverage
4. Document everything — keep proof of credible coverage in case you need it later
5. Plan ahead for retirement — know when your employer coverage ends and start your Medicare SEP timely
6. Talk to Sage PLUS at 1-888-875-9229 for free, unbiased counseling

The Part B late enrollment penalty

If you delay Part B without qualifying for an SEP, you pay a permanent penalty:

• 10% of the Part B premium for every full 12-month period you could have had Part B but didn't
• The penalty applies for as long as you have Part B (i.e., the rest of your life)
• Example: 5 years of delay = 50% permanent premium increase = roughly $100/month extra in 2026 dollars

This penalty is one of the most costly mistakes a Medicare beneficiary can make. The 20-employee rule is your protection — make sure you understand whether it applies to you.

Frequently asked questions

Can I delay Medicare if my employer has 20+ employees?

Yes — if you have credible group health coverage from a current employer with 20 or more employees, you can typically delay Medicare Part B without penalty. Confirm with HR that your coverage qualifies, and document it in writing.

What if I have COBRA — can I delay Medicare?

No. COBRA is not credible coverage for delaying Medicare. If you're on COBRA at 65 (or become eligible for Medicare while on COBRA), you generally need to enroll in Medicare during your Initial Enrollment Period to avoid late penalties.

Can I keep contributing to my HSA after enrolling in Medicare?

No. Once you enroll in any part of Medicare (including Part A), you become ineligible to contribute new funds to an HSA. You can still use existing HSA funds. If you want to keep contributing, you must delay Medicare entirely.

How does the 8-month Special Enrollment Period work?

When your active employment or employer coverage ends, you get an 8-month window to enroll in Medicare Part B without late penalty. Apply through Social Security at ssa.gov or 1-800-772-1213. Don't wait — gaps in coverage can result.

Should I enroll in Part A at 65 even if I'm working?

Usually yes — Part A is free for most workers and can help with hospital costs as secondary insurance. The exception: if you have an HSA-qualified plan and want to keep contributing to your HSA, delay Part A until you stop using the HSA.