Medicare Enrollment Guide 2026 – When and How to Sign Up

✍️ BeSecuredNow Editorial Team | 📅 August 2026 | ⏱️ 5 min read

Key Takeaway: Enroll in Medicare Part B during your Initial Enrollment Period (IEP) — 3 months before to 3 months after your 65th birthday month. Late Part B enrollment triggers a 10% premium penalty per year late — permanent for as long as you have Part B. If you have employer coverage, special rules apply.

Medicare Enrollment Periods Explained

Enrollment Period	When	Who It's For
Initial Enrollment Period (IEP)	7-month window around 65th birthday	First-time Medicare enrollees
Special Enrollment Period (SEP)	8 months after losing employer coverage	Those with creditable employer coverage at 65
General Enrollment Period (GEP)	Jan 1 – Mar 31 annually	Missed IEP, no SEP qualifier
Medicare Advantage Open Enrollment	Oct 15 – Dec 7 annually	Switch/change Medicare Advantage or Part D
Medicare Advantage Open Enrollment (2)	Jan 1 – Mar 31 annually	Switch MA plans or return to Original Medicare

Initial Enrollment Period (IEP) — Most Important

Your IEP is a 7-month window: 3 months before your birthday month, your birthday month, and 3 months after. Enrolling in the first 3 months means Part B coverage starts on the first day of your birthday month. Enrolling after your birthday month means a 1–3 month delay in coverage starting.

Still Working at 65 with Employer Insurance

If your employer has 20+ employees and you're covered by their group health plan, you can delay Medicare Part B enrollment without penalty. Your Special Enrollment Period begins when you lose that coverage (retire or lose eligibility). You have 8 months to enroll in Part B without a late penalty. COBRA does NOT count as qualifying employer coverage for this purpose.

Medicare Part A — Usually Automatic

If you've worked 40+ quarters (10 years) paying Medicare taxes, Part A is free. Most people are automatically enrolled in Part A at 65 if they're receiving Social Security benefits. If not receiving SS benefits yet, you must actively enroll. Part A is free, so enroll immediately — there's no reason to delay.

Late Enrollment Penalties

Part B penalty: 10% per 12-month period you were eligible but not enrolled. If you were late by 2 years, your Part B premium increases 20% — permanently.

Part D penalty: 1% of the national base beneficiary premium per month late — also permanent. On a $36 base premium, being 24 months late adds $8.64/month — every month, forever.

Frequently Asked Questions

How do I sign up for Medicare?

Apply online at ssa.gov, call Social Security at 1-800-772-1213, or visit your local Social Security office. If you're already receiving Social Security benefits, you'll be automatically enrolled in Parts A and B at 65. Apply for Part D and Medicare Advantage plans separately through Medicare.gov or a licensed insurance agent.

Can I work and have Medicare at the same time?

Yes — you can have both Medicare and employer insurance simultaneously. Medicare coordinates with employer coverage based on whether your employer has 20 or more employees. With small employers (under 20), Medicare is primary. With large employers (20+), employer insurance is primary and Medicare is secondary.

What if I'm disabled and under 65?

Medicare is available to people under 65 who have received Social Security Disability Insurance (SSDI) for 24 months, have ALS (immediate eligibility), or have end-stage renal disease (ESRD). The same enrollment rules and penalties apply as for age-based Medicare.