You generally sign up for Medicare during a specific 7‑month window around your 65th birthday. The exact timing can change if you are still working or have other coverage.
Basic sign-up window
Most people first become eligible for Medicare at age 65 and have an Initial Enrollment Period that lasts 7 months: it starts 3 months before the month you turn 65, includes your birthday month, and ends 3 months after that month. Enrolling in this window usually helps you avoid gaps in coverage and late enrollment penalties.
If you are already on Social Security
If you are already receiving Social Security or Railroad Retirement Board benefits at least a few months before turning 65, you are typically enrolled automatically in Medicare Part A and Part B and get your Medicare card in the mail. You can choose to decline Part B if you do not want to pay the monthly premium right away.
If you keep employer coverage
If you or your spouse are actively working and covered by a qualifying employer plan, you may be able to delay Part B and use a Special Enrollment Period later without a penalty. In that case, you can sign up for Part B anytime while that job-based coverage is in place or within 8 months after the employment or coverage ends.
If you miss your first chance
If you do not qualify for a Special Enrollment Period and miss your Initial Enrollment Period, you can enroll in Part A and/or Part B during the General Enrollment Period from January 1 through March 31 each year. Coverage then starts the month after you enroll and you may owe a late enrollment penalty, depending on how long you waited.
When to get help
The exact best time for you can depend on your job status, your spouse’s coverage, and whether you have Medicaid or other insurance. For personalized guidance, contact Social Security or visit the official Medicare website and use their “When can I sign up?” tool, or speak with a local State Health Insurance Assistance Program (SHIP) counselor.
