File for Medicare in the Three Months Before Your 65th Birthday

You should file for Medicare during the three-month period before the month you turn 65. This window is called your Initial Enrollment Period, and it runs from three months before your birthday month through three months after. For example, if you turn 65 in June, your Initial Enrollment Period spans March through September.

The reason to file early—rather than waiting until your birthday month—is that Medicare coverage typically begins on the first day of the month you turn 65, but only if you file during that three-month window before. If you file after your birthday month passes, your coverage will start later, and you may face a gap in health insurance.

You can file online at Medicare.gov, by phone at 1-800-MEDICARE, or in person at your local Social Security office. The online process takes about 15 minutes if you have your Social Security number and basic health information ready.

Key Takeaways

  • File for Medicare during the three months before you turn 65 so coverage begins on the first of your birthday month.
  • If you miss your Initial Enrollment Period, you can still file, but your coverage will start later and you may owe a permanent penalty on your premiums.
  • You do not have to file at 65 if you are still working and have health insurance through your employer—you have eight months after you leave that job to file without penalty.
  • File online at Medicare.gov, by phone at 1-800-MEDICARE, or at your local Social Security office.
  • Have your Social Security number, birth date, and current health insurance information ready when you file.

What Happens If You Miss the Three-Month Window

If you do not file during your Initial Enrollment Period, you can still file later, but your coverage will not begin until the first of the month after you file. More importantly, you may owe a late enrollment penalty added to your monthly premium for as long as you have Medicare.

The penalty is calculated as 10 percent of the standard Part B premium for each full 12-month period you were not enrolled. If the standard Part B premium is $165 per month and you were late by two years, you would owe an extra $33 per month permanently. This penalty does not go away if you enroll later.

There is one major exception: if you were covered by health insurance through an employer while you were working, you have eight months after you leave that job or lose that coverage to file without penalty. This is called your Special Enrollment Period. You will need to show proof that you had employer coverage—usually a letter from your employer or your insurance card.

File Before You Retire if You Are Still Working

If you are still working at 65 and have health insurance through your job, you do not have to file for Medicare right away. However, you should still file during your Initial Enrollment Period (the three months before your birthday) to avoid the late penalty later, even if you do not set up your coverage yet.

When you file but do not set up Part B (the doctor and outpatient coverage), you are protecting yourself from future penalties. Your Part A (hospital insurance) will be active, but Part B will not charge you a premium or enroll you in a plan until you choose to set up it. This is different from declining Medicare entirely—if you decline, you lose the protection against the late penalty.

Once you retire or lose your employer coverage, you have eight months to set up Part B without penalty. After that window closes, the late penalty applies.

How to File and What Documents You Need

You can file for Medicare through three routes: online at Medicare.gov (the fastest option), by phone at 1-800-MEDICARE, or in person at your local Social Security office. Online filing usually takes 10 to 15 minutes.

Have these items ready before you start: your Social Security number, your birth date, your citizenship or immigration status, and information about any health insurance you currently have. If you are filing in person, bring your Social Security card and a photo ID. If you are filing by phone, have your Social Security number visible so you can answer verification questions quickly.

After you file, Medicare will send you a confirmation letter and your Medicare card in the mail within two to three weeks. Your coverage begins on the date listed in that letter, which is usually the first of your birthday month if you filed during your Initial Enrollment Period.

Special Cases: Government Employees and Railroad Workers

If you worked for the federal government or certain state and local governments, you may have different rules. Federal employees covered under the Federal Employees Health Benefits Program (FEHB) have the same eight-month grace period as other workers with employer coverage. You do not have to file at 65 if you are still covered by FEHB, but you should file during your Initial Enrollment Period to avoid the late penalty.

Railroad workers covered under the Railroad Retirement Board have their own enrollment process separate from Social Security. If you receive railroad retirement benefits, contact the Railroad Retirement Board directly at 1-877-772-5772 rather than filing through Medicare.gov.

File Early to Avoid Coverage Gaps and Penalties

The safest approach is to file during the first month of your three-month Initial Enrollment Period—three months before you turn 65. This gives Medicare time to process your process, send your card, and may support coverage begins on the first of your birthday month with no gap.

If you file in the second or third month of your window, coverage may not begin until the following month, leaving you uninsured for a period. If you file after your Initial Enrollment Period ends, you will face a delayed start date and a permanent penalty on your premiums.

The only exception is if you have employer coverage when you turn 65. In that case, you can file anytime during your Initial Enrollment Period and set up coverage later, as long as you file before the window closes.

Frequently Asked Questions

What if I turn 65 and I am still working?

You do not have to file for Medicare right away if you have health insurance through your job. However, file during your Initial Enrollment Period (three months before your birthday) to protect yourself from the late penalty. You can set up coverage later when you retire, as long as you file before the window closes.

Can I file for Medicare before I turn 65?

You can file starting three months before your birthday month. You cannot file earlier than that. If you are younger than 65 and have End-Stage Renal Disease or ALS, different rules explore—contact Medicare at 1-800-MEDICARE to learn about your options.

What happens if I file after my birthday month?

Your coverage will start on the first of the month after you file, not on your birthday. You will also owe a late enrollment penalty added to your Part B premium for as long as you have Medicare, unless you had employer coverage when you turned 65.

Do I have to file in person, or can I do it online?

You can file online at Medicare.gov, by phone at 1-800-MEDICARE, or in person at your local Social Security office. Online filing is usually the fastest option and takes about 15 minutes.

What if I am not a U.S. citizen?

You must be a U.S. citizen or a lawful permanent resident who has lived in the United States for at least five years to file for Medicare. When you file, you will need to provide proof of your immigration status. Contact Medicare at 1-800-MEDICARE if you have questions about your specific situation.