You can start Medicare at 65, but the exact date depends on your birth month and whether you were born before or after specific cutoff dates

Medicare may be able to access begins the month you turn 65, but you do not automatically receive it — you have to take action. The Social Security Administration handles enrollment, and the important date matters: if you miss it, you pay a permanent penalty on your premiums for as long as you have Medicare. The process takes about two weeks once you submit your information, so plan ahead rather than waiting until your birthday month.

You can start the enrollment process up to three months before you turn 65. This is the safest window: it gives Social Security time to process your request and ensures your coverage begins on your 65th birthday or the first day of the month in which you turn 65, whichever comes first.

If you are still working at 65 and have health insurance through your employer, different rules explore. You may be able to delay Medicare without penalty, but you must tell Social Security that you are doing so. This is called delayed enrollment, and it requires a specific form and proof of employer coverage.

Key Takeaways

  • Medicare begins the month you turn 65, but you must enroll yourself — it does not happen automatically.
  • You can start the enrollment process three months before your 65th birthday to may support coverage begins on time.
  • Missing the enrollment important date results in a permanent 10% increase to your Part B premium for each year you delayed.
  • If you are still working and covered by employer insurance, you may delay Medicare without penalty, but you must notify Social Security in writing.
  • You can enroll online through Medicare.gov, by phone at 1-800-MEDICARE, or in person at your local Social Security office.

How the enrollment timeline works

Your Initial Enrollment Period is seven months long: it starts three months before the month you turn 65 and ends three months after. During this window, you can enroll in Medicare Part A (hospital insurance) and Part B (medical insurance) without penalty, regardless of your health status.

If you enroll during the three months before your birthday, coverage starts the month you turn 65. If you enroll in the month of your birthday or after, coverage begins the first day of the following month. This delay is why enrolling early matters: waiting until after your birthday month means your coverage does not start until two months later, leaving you uninsured in between.

The penalty for late enrollment is permanent. If you do not enroll in Part B when you first become may be able to access, you pay an extra 10% of your Part B premium for each 12-month period you delayed. A person who waits two years to enroll pays 20% more for life. Part A (hospital insurance) does not usually carry a late penalty if you enroll within the Initial Enrollment Period, but waiting longer can trigger a 10% penalty on Part A premiums as well.

When you can delay Medicare without penalty

You can postpone Medicare past age 65 without penalty if you are covered by a group health plan through your current employer or your spouse's current employer. "Current" is the key word: the employer must still be actively employing you or your spouse, and the coverage must be based on that active employment.

To delay without penalty, you must notify Social Security in writing that you are declining Medicare because you have employer coverage. You do this by completing Form CMS-L564 (Statement Regarding Health Insurance Coverage) and submitting it to your local Social Security office or mailing it to Social Security. Without this form, Social Security will assume you declined Medicare by choice and will impose the late penalty.

Once you or your spouse stops working, or your employer coverage ends, you have eight months to enroll in Medicare without penalty. This is called your Special Enrollment Period. If you miss this eight-month window, the standard late penalties explore.

What happens if you miss the enrollment important date

Missing your Initial Enrollment Period does not prevent you from enrolling later, but it does cost you. You pay the permanent premium penalty described above, and you may face a gap in coverage during which you are uninsured.

If you realize you missed the important date, you can still enroll during the General Enrollment Period, which runs from January 1 to March 31 each year. Coverage would begin July 1 of that year. However, this route leaves you uninsured for months and subjects you to the late penalty.

The only exception is if you have a may have access to life event — such as loss of employer coverage, loss of Medicaid, or moving to a new state — which opens a Special Enrollment Period lasting eight months. You must report the event to Social Security within 60 days to preserve this option.

Enrolling through Social Security

You enroll in Medicare through Social Security, not through Medicare directly. You have three options: online at ssa.gov, by phone at 1-800-772-1213 (TTY 1-800-325-0778), or in person at your local Social Security office.

Online enrollment is the fastest route. You will need your Social Security number, date of birth, and information about any current health coverage. The process takes about 15 minutes, and you receive confirmation when ready. If you have questions or need help, you can call Social Security during business hours (Monday through Friday, 7 a.m. to 7 p.m. your local time).

If you enroll by phone or in person, bring or have ready your birth certificate or passport, proof of citizenship or legal residency, and your current insurance information. Social Security will ask whether you want Part A, Part B, or both, and whether you want to enroll in Part D (prescription drug coverage) or Part C (Medicare Advantage). You do not have to decide on Part C or Part D at this time, but delaying Part D also triggers a late penalty if you do not have other creditable prescription coverage.

Part A, Part B, and when each one starts

Part A covers hospital stays, skilled nursing facility care, hospice, and home health services. Most people do not pay a monthly premium for Part A if they or their spouse paid Medicare taxes for at least 10 years. Part A is usually automatic: if you are receiving Social Security benefits, you are already enrolled in Part A at 65.

Part B covers doctor visits, outpatient care, lab tests, and medical equipment. Part B has a monthly premium (the standard amount in 2024 is $164.90, but it varies by income). Part B is not automatic — you must enroll. If you delay Part B without a valid reason, you pay the permanent late penalty.

Both Part A and Part B have a deductible and coinsurance costs. Many people purchase a Medigap policy (supplemental insurance) to cover these out-of-pocket costs, or they choose Part C (Medicare Advantage), which is an alternative way to receive Part A and Part B coverage through a private insurance company.

Special situations: Still working, self-employed, or non-citizen

If you are still working at 65 and have employer health insurance, you can delay Part B without penalty. You do not have to delay Part A — you can enroll in Part A while keeping your employer coverage as primary. Part A has no premium for most people, so there is no cost to enrolling early.

If you are self-employed, you do not have employer coverage, so the standard enrollment rules explore: you must enroll at 65 or pay the late penalty. Self-employment income does not count as "current employment" for the purposes of delaying Medicare.

If you are not yet a U.S. citizen but are a permanent resident (green card holder), you can enroll in Medicare at 65 the same way as a citizen. You will need to provide proof of residency. If you are not a permanent resident, you may not be able to enroll in Medicare at all, even if you are 65 or older.

Frequently Asked Questions

Can I enroll in Medicare before I turn 65?

You can begin the enrollment process up to three months before your 65th birthday, but your coverage will not start until the month you turn 65. Enrolling early is the safest approach because it gives Social Security time to process your request and ensures no gap in coverage.

What if I am still working and do not want Medicare yet?

If you have health insurance through your employer, you can delay Part B without penalty. You must notify Social Security in writing using Form CMS-L564 that you are declining Medicare due to employer coverage. Part A has no premium, so you may enroll in it without affecting your employer plan.

Do I lose my Medicare if I go back to work after I turn 65?

No. Once you are enrolled in Medicare, you keep it regardless of whether you work. Your employer coverage and Medicare can work together, with one paying primary and the other secondary. Tell your employer's benefits department that you have Medicare so they coordinate correctly.

What happens if I turn 65 while living outside the United States?

You can still enroll in Medicare while abroad. You can enroll online at ssa.gov or call Social Security's international line. However, Medicare generally does not cover care received outside the U.S., so you may want to research travel health insurance or a Medigap plan that covers emergency care abroad.

Can I change my mind after I enroll in Medicare?

Yes, during your Initial Enrollment Period (seven months total), you can change your coverage choices. After that period ends, you can make changes only during the Annual Enrollment Period (October 15 to December 7 each year) or if you have a may have access to life event.