Medicare Enrollment

When to sign up for Medicare

• Initial Enrollment Period: 7 months, from 3 months before the month you turn 65 to 3 months after. Signing up before your birthday month means coverage starts when you turn 65.
• General Enrollment Period: January 1 to March 31 each year if you missed your initial window; coverage starts the month after you sign up, and penalties may apply.
• Special Enrollment Period: if you (or your spouse) are still working with large-employer group coverage, you have 8 months after that job or coverage ends, whichever comes first, to sign up without a penalty.

COBRA and retiree coverage don't count as current employment coverage: they don't give you a Special Enrollment Period, so sign up for Part B on time even if you take COBRA.

Late penalties

Part B: 10% of the standard premium for each full 12-month period you could have had it, for as long as you have Part B. Medicare's example: 2 years late = 20%, or $40.58 a month on top of the $202.90 premium in 2026. Part D: 1% of the national base premium ($38.99 in 2026) times the months you went without creditable drug coverage (63+ days in a row), also for life. Part A, if you must buy it, costs 10% more for twice the years you delayed. See Medicare D for drug costs.

Common questions

Sources

• Medicare.gov: When does Medicare coverage start?
• Medicare.gov: Avoid late enrollment penalties
• Medicare.gov: How much does Medicare drug coverage cost?

More retirement calculators: Mega Backdoor Roth

Related

• Medicare D
• Medicare Advantage
• COBRA health insurance
• Medicare Plan G

General information, not financial, tax or legal advice. Check important numbers with the official source before acting on them.