When to File for Medicare: Deadlines and Enrollment Periods

File for Medicare in the Three Months Before You Turn 65

You can file for Medicare starting three months before the month you turn 65. Most people should file during this window — it is called your Initial Enrollment Period, and it lasts seven months total (three months before, the month you turn 65, and three months after). Filing early means your coverage starts on the first day of the month you turn 65, with no gap.

If you wait until after that seven-month window closes, you may face a permanent penalty on your premiums. The penalty is 10 percent per year of delay for Part B (doctor and outpatient care) and 1 percent per month of delay for Part D (prescription drugs). These penalties stay with you for life, so the cost of filing late compounds every year.

You do not have to be retired to file for Medicare at 65. Age is the only requirement for most people. If you are still working and have health insurance through your employer, you may have different rules — see the section below on working past 65.

Key Takeaways

Your Initial Enrollment Period runs for seven months: three months before you turn 65, the month of your birthday, and three months after.
Filing during this window means coverage starts on the first day of the month you turn 65 with no waiting period.
If you miss the important date and do not have employer coverage, you pay a permanent penalty on Part B and Part D premiums for the rest of your life.
You can file online at Medicare.gov, by phone at 1-800-MEDICARE, or in person at your local Social Security office.
If you are still working with employer health insurance, you may be able to delay Medicare without penalty under the Special Enrollment Period.

How to File: Three Routes

You have three ways to file for Medicare. The fastest is online at Medicare.gov — you can complete the form in about 15 minutes if you have your Social Security number and basic health history ready. You will get a confirmation number on screen and can check your process status online afterward.

You can also call 1-800-MEDICARE (1-800-633-4227) and speak to someone who will file for you over the phone. Wait times are usually shorter in the morning and on weekdays. Have your Social Security card and a list of any current medications or health conditions nearby when you call.

A third option is to visit your local Social Security office in person. This takes longer — you will need an appointment, which you can book online at ssa.gov — but some people prefer it if they have questions or need help reading forms. Bring your Social Security card, birth certificate, and proof of citizenship (passport, naturalization papers, or state ID).

What Happens If You Are Still Working at 65

If you have health insurance through your current employer, you may not need to file for Medicare right at 65. This depends on your employer's size. If your employer has 20 or more employees, you can delay Medicare Part B without penalty as long as you stay enrolled in the employer plan. You have eight months after you leave that job to file for Part B without penalty — this is called the Special Enrollment Period.

Part A (hospital insurance) is different. Most people should file for Part A even if they are working, because it is usually free and has no penalty for delay. Part D (prescription drugs) does carry a penalty if you delay, unless your employer plan covers drugs at least as well as Medicare does. Ask your employer's benefits office whether your plan is "creditable coverage" for drugs — if it is, you can delay Part D without penalty.

The key is to file for Part A, and to understand your employer plan's drug coverage, before you turn 65. If you are unsure, call 1-800-MEDICARE and describe your situation — they can tell you what you need to do.

Missing the important date: Penalties and How to Recover

If you miss your Initial Enrollment Period and do not have employer coverage or another may have access to reason, you will pay a permanent penalty. For Part B, the penalty is 10 percent of the standard premium for each full year you were may be able to access but not enrolled. If the standard Part B premium is $165 per month and you delayed three years, your penalty would be 30 percent — an extra $49.50 per month for life.

Part D penalties work differently. You pay 1 percent of the national average Part D premium for each month you were not enrolled. If you delay one year (12 months), that is a 12 percent penalty. Like Part B, this penalty is permanent.

You can still file after the important date, but the penalty applies when ready. There is no "catch-up" period to avoid it. The only exceptions are if you had a may have access to life event (loss of employer coverage, loss of other insurance, or a move to a new state) or if you were receiving Social Security benefits before 65 — in those cases, you may be able to file without penalty during a Special Enrollment Period.

Automatic Enrollment at 65 If You Receive Social Security

If you are already receiving Social Security retirement or disability benefits when you turn 65, Medicare will enroll you automatically in Parts A and B. You do not have to file — Social Security will send you a Medicare card about three months before your 65th birthday. You can refuse this coverage if you want, but you must do so in writing within a specific timeframe or the enrollment stands.

Automatic enrollment does not include Part D (prescription drugs). You still need to file for Part D separately during your Initial Enrollment Period, or you will face a penalty if you delay. You can file for Part D online, by phone, or in person using the same methods described above.

What Documents You Need to Have Ready

To file for Medicare, gather these documents before you start:

Your Social Security number
Your birth certificate or passport
Proof of citizenship or legal residency (naturalization papers, green card, or state ID)
A list of current medications and any chronic health conditions
Your current health insurance information (if you have it)
Your employer's name and dates of employment (if you are still working)

You do not need all of these for every filing method. Online filing requires your Social Security number and basic health history. Phone filing is the same. In-person filing at Social Security requires more documentation — bring everything listed above to be safe.

If you are filing for Part D (prescription drugs), have a list of your current medications ready, including the dose and how often you take each one. This helps the program estimate your costs under different plans.

Frequently Asked Questions

Can I file for Medicare before I turn 65?

You can file starting three months before the month you turn 65. If you file earlier than that, your process will be rejected and you will have to resubmit it during the correct window. There is no advantage to filing more than three months early.

What if I miss the important date by a few weeks?

You have seven months total in your Initial Enrollment Period. If you miss it by a few weeks, you may still be within that window. Check the exact dates: three months before your birthday month, your birthday month, and three months after. If you are past that, you will face a permanent penalty unless you have a may have access to reason for late filing.

Do I have to file for all four parts of Medicare at once?

No. You can file for Part A and Part B together, but Part D (drugs) is separate. Many people file for A and B at 65 and then choose a Part D plan later. However, delaying Part D past your Initial Enrollment Period triggers a penalty, so it is usually better to file for it at the same time even if you do not use it yet.

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

You must be a U.S. citizen or have been a lawful permanent resident for at least five years to file for Medicare. If you are not yet a citizen but are a green card holder and have lived in the U.S. for five years, you may be able to file. Call 1-800-MEDICARE with your immigration status and they can tell you whether you meet the requirements.

Can I change my mind after I file?

Yes. You have a limited time to change your coverage choices after you enroll. For Part A and Part B, you can change your mind within a certain window. For Part D, you can switch plans once per year during the annual enrollment period (October 15 to December 7). If you made a mistake during your Initial Enrollment Period, contact Medicare when ready to see what options you have.

This guide is for general information only and is not medical, financial, legal, or other professional advice. For decisions specific to your situation, consult a qualified professional. See our Editorial Policy.