File for Medicare Part A three months before you turn 65

The best time to file for Medicare Part A is during the three-month window that starts three months before your 65th birthday and ends on your birthday itself. This is called your Initial Enrollment Period, and it is the window where you avoid late penalties and coverage gaps.

If you were born on June 15, you can file starting March 15. Your coverage can start as early as June 1 of that year — the first day of the month in which you turn 65 — if you file by the end of that month. Filing during this window means Part A coverage begins without delay and without penalty, even if you do not need it right away.

The Social Security Administration handles Medicare enrollment. You can file online at ssa.gov, by phone at 1-800-772-1213, or in person at your local Social Security office. You will need your birth certificate, proof of citizenship or legal residency, and your Social Security number.

Key Takeaways

  • Your Initial Enrollment Period runs from three months before your 65th birthday through the end of the month you turn 65, and filing during this window avoids late penalties.
  • Part A coverage can begin as early as the first day of the month you turn 65 if you file by the end of that month.
  • If you miss your Initial Enrollment Period, you can file during the General Enrollment Period (January 1 to March 31 each year), but your coverage will not start until July 1 and you may owe a penalty.
  • You do not need to file if you are already receiving Social Security benefits — Medicare Part A is enrolled automatically three months before your 65th birthday.
  • Working past 65 and having employer health coverage may let you delay filing without penalty, but you must file within eight months of leaving that job.

What happens if you file after your Initial Enrollment Period

If you miss the three-month window before your birthday, you can still file during the General Enrollment Period, which runs January 1 through March 31 each year. However, coverage does not begin until July 1 of that year, creating a gap of several months with no Part A protection.

More importantly, you will owe a late enrollment penalty on your Part A premiums for as long as you have Medicare. The penalty is 10 percent of the standard premium for each full year you could have had Part A but did not. If you wait five years to file, you pay 50 percent more than someone who filed on time — and that extra cost stays with you permanently.

The only exception is if you had creditable coverage — employer health insurance or union coverage — that lasted until you filed. If you were covered by an employer plan when you turned 65 and filed within eight months of losing that coverage, you do not owe a penalty. You will need to show proof of that coverage when you file, such as a letter from your employer or insurance company stating the coverage dates and that it was creditable.

If you are already receiving Social Security

You do not need to take any action. Social Security automatically enrolls you in Medicare Part A three months before your 65th birthday. Your Part A coverage begins the first day of the month you turn 65, and you will receive your Medicare card in the mail about two weeks before that date.

This automatic enrollment happens whether or not you have filed for Social Security retirement benefits. If you are receiving Supplemental Security Income (SSI) or Social Security Disability Insurance (SSDI), the same automatic process applies — you are enrolled at 65 without having to file again.

If you are still working at 65

If you are covered by your employer's health plan when you turn 65, you may be able to delay filing for Part A without penalty. This is called creditable coverage, and it protects you from the late enrollment penalty as long as your employer coverage lasts.

However, you must file for Part A within eight months of the date your employer coverage ends — whether that is because you retire, leave the job, or the coverage ends for another reason. If you wait longer than eight months, the penalty applies. Keep the date your coverage ended, because you will need to report it when you file.

Even if you delay Part A, you should still file for Medicare Part B and Part D (prescription drug coverage) during your Initial Enrollment Period to avoid penalties on those parts. Part A is the only part where working past 65 with creditable coverage gives you a penalty waiver.

Special situations: Disability and end-stage renal disease

If you are under 65 and receive Social Security Disability Insurance (SSDI), you are automatically enrolled in Medicare Part A after you have been on disability for 24 months. You do not need to file — Medicare begins automatically, and your card arrives in the mail.

If you have end-stage renal disease (ESRD) — permanent kidney failure requiring dialysis or transplant — you may be able to file for Part A at any age. The rules are different for ESRD, and you should contact Social Security or your dialysis center to understand your specific timeline, because coverage can begin as soon as the month your treatment starts.

How to file and what documents you need

You have three ways to file: online, by phone, or in person. Online filing through ssa.gov/benefits/retirement is usually the fastest and lets you file from home. You can also call Social Security at 1-800-772-1213 (TTY 1-800-325-0778) Monday through Friday, 7 a.m. to 7 p.m. your local time. In-person filing happens at your local Social Security office — find yours at ssa.gov/locator.

Bring or have ready: your birth certificate (original or certified copy), proof of U.S. citizenship or legal residency (passport, naturalization papers, or green card), your Social Security number, and proof of residence if you are filing in person (utility bill, lease, or mortgage statement dated within the last two months). If you are filing based on creditable coverage, bring a letter from your employer or former employer stating the dates your coverage was active.

Processing usually takes two to four weeks. You will receive a notice in the mail confirming your enrollment, and your Medicare card arrives separately about two weeks before your coverage begins.

Frequently Asked Questions

What if I turn 65 on the first day of the month?

Your Initial Enrollment Period still runs three months before that date through the end of that month. If you turn 65 on June 1, you can file starting March 1 and your coverage can begin June 1 if you file by June 30. Filing by the end of the month you turn 65 ensures no gap.

Do I have to file if I do not plan to use Medicare right away?

You should file during your Initial Enrollment Period even if you do not think you need it, because waiting costs you. If you miss the window and file later, you owe a permanent penalty on Part A premiums. The only exception is if you have creditable employer coverage that lasts past 65.

Can I change my mind after I file?

Yes. You have a limited time to change your enrollment — usually through the end of the month following the month you enrolled. Contact Social Security to make changes. After that window closes, you can only change during the General Enrollment Period (January 1 to March 31) or if you have a may have access to life event.

What if I do not know my Social Security number?

Contact Social Security at 1-800-772-1213 or visit your local office. Bring identification and proof of citizenship. They can look up your number and help you file at the same time.

Does filing for Part A mean I have to file for Part B at the same time?

No. Part A and Part B are separate. However, you should file for Part B during your Initial Enrollment Period too, because missing that important date for Part B carries its own penalty. If you are still working with creditable coverage, the rules for Part B are different — ask Social Security about your specific situation.