Medicare basics
What Is Medicare and When Can You Enroll?
Learn the basics of Medicare and the enrollment periods that may apply as you become eligible or make coverage changes.
The short answer
What is Medicare and when can you enroll?
Medicare is federal health insurance for people age 65 or older and certain younger people with disabilities or qualifying conditions. Enrollment timing depends on your circumstances, including your age, current coverage, and whether you qualify for a Special Enrollment Period.
What Medicare covers
Original Medicare includes Part A, which helps cover inpatient hospital care and certain related services, and Part B, which helps cover outpatient care, doctor services, preventive services, and medical supplies. Many people also consider prescription drug coverage or other coverage options that work with Medicare.
Key enrollment periods
- ✓Initial Enrollment Period: for many people, a seven-month window around the month they turn 65.
- ✓General Enrollment Period: January 1 through March 31 each year for people who did not sign up when first eligible and do not qualify for another enrollment period.
- ✓Special Enrollment Period: may apply after certain life events, such as losing qualifying employer coverage or moving out of a plan's service area.
- ✓Medicare Advantage and Part D Open Enrollment: October 15 through December 7 each year for changes effective the following year.
Confirm your timing before you act
Enrollment rules and timing can depend on current employer coverage, retiree coverage, Social Security benefits, disability, and other individual facts. Medicare and Social Security are the authoritative sources for enrollment eligibility and deadlines. A licensed advisor can help explain insurance options they are authorized to represent, but does not replace official enrollment guidance.
Frequently asked questions
Do I get Medicare automatically when I turn 65?
Some people are enrolled automatically, while others need to apply. Whether you receive Social Security or Railroad Retirement Board benefits can affect the process.
What happens if I miss Medicare enrollment?
You may need to wait for another enrollment period, and late enrollment penalties can apply in some situations. Check Medicare.gov or Social Security for guidance that matches your circumstances.
Can I delay Medicare if I am still working?
It depends on the employer coverage and your situation. Confirm how active employer coverage works with Medicare before delaying Part B or Part D.
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Last reviewed August 13, 2026. Medicare rules and plan details can change; verify current information with Medicare, Social Security, official plan materials, and properly licensed professionals.