The best time to enroll in Medicare is during your Initial Enrollment Period, which is a 7-month window that includes the 3 months before your 65th birthday month, your birthday month, and the 3 months after. Enrolling during the first 3 months ensures your coverage starts the month you turn 65 with no gap in coverage.
Missing your Initial Enrollment Period can have serious consequences. If you delay enrolling in Part B without qualifying for an exception, you’ll face a permanent late enrollment penalty of 10% for each full 12-month period you could have had Part B but didn’t sign up. This penalty is added to your monthly premium for as long as you have Medicare.
Most people get Part A premium-free if they or their spouse worked and paid Medicare taxes for at least 40 quarters. Part B requires a monthly premium, which is $202.90 in 2026 for most beneficiaries, though higher earners pay more due to IRMAA surcharges.
The only valid reasons to delay Medicare enrollment past 65 are if you have creditable coverage through current employment for you or your spouse, or if you qualify for other special circumstances.