Most people first become eligible for Medicare at age 65, but some people can qualify earlier because of a disability, ALS, or End-Stage Renal Disease (ESRD). The key is not only knowing your age, but also knowing whether you’ll be enrolled automatically or need to sign up yourself.
When do you become eligible for Medicare?
Medicare is generally available to people age 65 or older who meet Medicare’s citizenship or residency requirements. Some people under 65 may qualify earlier if they have a qualifying disability, ALS, or ESRD.
For most people, the first Medicare enrollment window is a 7-month Initial Enrollment Period. It usually starts 3 months before the month you turn 65, includes your birthday month, and ends 3 months after that month.
If your birthday falls on the first day of a month, Medicare uses a slightly different timing rule. In that case, your enrollment period starts 4 months before you turn 65, ends 2 months after your birthday month, and coverage can begin the first day of the month before you turn 65.
What benefits can start at Medicare eligibility age?
When you enroll in Medicare, your basic federal coverage starts with Part A and Part B.
| Medicare part | What it helps cover |
|---|---|
| Part A | Inpatient hospital care, skilled nursing facility care, hospice care, and some home health care |
| Part B | Doctor services, outpatient care, home health care, durable medical equipment, and many preventive services |
| Part D | Prescription drug coverage through a Medicare drug plan or a Medicare Advantage plan that includes drug coverage |
After you have Medicare, you generally choose between Original Medicare and a Medicare Advantage plan. Original Medicare includes Part A and Part B. Medicare Advantage is offered by private companies approved by Medicare and includes Part A and Part B, usually with Part D as well.
Will you get Medicare automatically?
Some people do, and some do not.
- Usually automatic: If you start getting Social Security or Railroad Retirement Board benefits at least 4 months before turning 65, you’ll generally be enrolled in Part A and Part B automatically.
- Usually not automatic: If you are not yet getting those benefits when you approach age 65, you generally need to sign up through Social Security.
That difference matters because waiting too long to enroll in Part B can lead to delayed coverage and a late enrollment penalty unless you qualify for a Special Enrollment Period.
Can you delay Medicare after 65?
Sometimes, yes. If you have qualifying job-based group health coverage through your own current employment or your spouse’s current employment, you may be able to delay Part B and use a Special Enrollment Period later.
That Special Enrollment Period generally lasts for 8 months after the employment ends or the group health plan coverage ends, whichever happens first. COBRA and retiree coverage are not treated the same as active-employment group coverage for this rule.
If you have a Health Savings Account (HSA), Medicare notes that Premium-free Part A can start up to 6 months retroactively once you sign up after age 65, but not before you were eligible for it. Because Medicare coverage and HSA contributions can overlap, it’s important to verify timing before you enroll.
How coverage start dates work
Coverage start dates depend on when you sign up.
- If you qualify for premium-free Part A, Part A usually starts the month you turn 65.
- If you sign up for Part B before the month you turn 65, Part B usually starts the month you turn 65.
- If you sign up during your birthday month or one of the 3 months after, Part B generally starts the following month.
Simple checklist to verify your Medicare eligibility age
- Confirm whether you are turning 65 soon or may qualify earlier due to disability, ALS, or ESRD.
- Check whether you already receive Social Security or Railroad Retirement Board benefits.
- Find out whether you’ll be enrolled automatically or must sign up.
- Review whether you have current job-based group coverage that may affect Part B timing.
- Check whether you contribute to an HSA before choosing a Medicare start date.
- Compare Original Medicare with Medicare Advantage and drug coverage options after Parts A and B are in place.
FAQ
Is Medicare eligibility age always 65?
No. Age 65 is the usual eligibility age, but some people qualify earlier because of disability, ALS, or ESRD.
Do I need both Part A and Part B to join Medicare Advantage?
Yes. Medicare Advantage plans include Part A and Part B benefits, so you need both parts to join.
Can I wait to sign up if I am still working?
Possibly. If you have qualifying active-employment group coverage through your job or your spouse’s job, you may be able to use a Special Enrollment Period later. It is important to verify the type of coverage before delaying Part B.
Automatic Part B has location exceptions
If you live in Puerto Rico or outside the United States, receiving retirement benefits does not automatically sign you up for Part B. Check your enrollment notice and contact Social Security or the Railroad Retirement Board before relying on automatic coverage.
Related coverage questions
- How to Enroll in Medicare: Steps, Timing and Where to Get Help
- Who Is Eligible for Medicare? Age, Disability and Enrollment
- How to Verify Your Medicare Coverage and Plan Enrollment