File for Medicare in the three months before your 65th birthday

You should file for Medicare during the three-month window that starts three months before you turn 65. This means if your birthday is in June, you can file starting in March. Filing during this window ensures your coverage starts on the first day of the month you turn 65, with no gap.

If you miss this window, you can still file after 65, but your coverage will start later — usually the first of the month after you file, or sometimes the first of the following month. The longer you wait after 65, the longer you go without coverage, and you may face late enrollment penalties that increase your premiums permanently.

The three-month window is the same whether you are still working, retired, or self-employed. Your work status does not change when you should file.

Key Takeaways

  • File during the three months before your 65th birthday to have coverage start on the first day of the month you turn 65.
  • If you file after 65, your coverage starts later and you may pay a permanent penalty on your premiums for each year you delayed.
  • 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 and have health insurance through your employer, you may be able to delay Part B without penalty, but you must file for Part A on time.
  • Special enrollment periods exist for people who lose employer coverage or move to a new state, allowing you to file outside the normal window without penalty.

What happens if you file before the three-month window

You can file up to four months before your 65th birthday, but filing more than three months early does not speed up your coverage start date. If you file four months before you turn 65, your coverage will still start on the first day of the month you turn 65 — the same as if you filed three months before.

Filing early does not hurt you, but it also does not help. The only advantage is peace of mind that your paperwork is in. If you are organized and want to get it done, filing four months ahead is safe.

What happens if you file after 65

If you turn 65 and do not file during the three-month window, you enter what Medicare calls your Initial Enrollment Period, which lasts until three months after the month you turn 65. During this extended period, you can still file without penalty, but your coverage will not start until the first of the month after you file.

Once this extended period ends, filing late triggers a late enrollment penalty. For Part B, you pay an extra 10 percent of the standard premium for each full year you delayed, and this penalty stays on your bill for as long as you have Medicare. For Part D (prescription drug coverage), the penalty is 1 percent of the national average premium per month of delay. These penalties are permanent — they do not go away after a few years.

Example: If the standard Part B premium is $165 per month and you file two years late, you pay an extra $33 per month (10 percent × 2 years) for the rest of your life on Medicare. This adds up to thousands of dollars over time.

Special cases: When you can file late without penalty

Medicare has Special Enrollment Periods that let you file outside the normal window without paying a late penalty. The most common situations are losing employer health insurance, moving to a new state, or turning 65 while still employed and covered by your employer's plan.

If you are still working at 65 and your employer has 20 or more employees, you can delay Part B without penalty as long as you are covered by the employer plan. You must file for Part A on time, but Part B can wait. Once you leave the job or lose the employer coverage, you have eight months to file for Part B without penalty.

If you move to a new state, you have two months to file for Medicare without penalty. If you lose other health insurance (not employer coverage), you also have two months. These windows are shorter than the standard enrollment period, so act quickly if you fall into one of these categories.

Where and how to file

You can file for Medicare online at Medicare.gov, which is the fastest route. The online form takes about 10 minutes and you can do it from home. You will need your Social Security number, date of birth, and citizenship or immigration status.

You can also call 1-800-MEDICARE (1-800-633-4227) to file by phone. Wait times vary, but calling early in the morning on a weekday usually means shorter holds. A representative will walk you through the questions and file your paperwork on the spot.

A third option is to visit your local Social Security office in person. You will need to bring your Social Security card, birth certificate, and proof of citizenship (passport, naturalization papers, or state ID). This route takes longer because you need an appointment, but some people prefer handling it face-to-face.

Documents you will need to file

The documents required are minimal. You need your Social Security number, date of birth, and proof of U.S. citizenship or legal residency. If you are filing online, you can type these in. If you are filing by phone or in person, have them ready.

If you have changed your name since you got your Social Security number, bring a document showing the change — a marriage certificate, divorce decree, or court order. If you are filing in person at a Social Security office, bring your current state ID or passport as well.

You do not need to bring tax returns, pay stubs, or bank statements to file for Medicare itself. However, if you think you might be due for Extra Help (a program that pays some of your Part D costs), you may want to gather income information ahead of time, because the process for Extra Help can be filed at the same time.

Timeline: What to expect after you file

After you file, Medicare processes your paperwork and sends you a Medicare card in the mail. This usually takes one to three weeks. Your coverage starts on the date you were approved for, regardless of when the card arrives. You do not need to wait for the physical card to have coverage — your coverage is active as soon as Medicare confirms your filing.

You will receive a welcome packet with your card, a handbook explaining your coverage, and information about your plan options. Read the handbook or call the number on your card if you have questions about what is covered.

If you filed during the three-month window before 65, your coverage starts on the first day of the month you turn 65. If you filed after 65, coverage starts on the first day of the month after your filing is processed. In either case, you are covered from that date forward, even if you have not received your physical card yet.

Frequently Asked Questions

What if I turn 65 while I am still working?

You must file for Part A (hospital insurance) on time to avoid penalty. You can delay Part B (medical insurance) without penalty as long as your employer has 20 or more employees and you are covered by their health plan. Once you leave the job or lose coverage, you have eight months to file for Part B without penalty.

Can I file for Medicare before I turn 65?

Yes. You can file up to four months before your 65th birthday. Filing early does not speed up your coverage start date — it will still begin on the first day of the month you turn 65 — but it ensures your paperwork is processed in time.

What if I miss the important date and do not file until after my extended enrollment period ends?

You will owe a permanent late enrollment penalty on your premiums. For Part B, this is 10 percent of the standard premium for each year you delayed. For Part D, it is 1 percent of the national average premium per month of delay. These penalties stay on your bill for life.

Do I have to file for Medicare if I am still working and have employer insurance?

You must file for Part A on time, even if you are still working. You can delay Part B if your employer has 20 or more employees and covers you. If your employer has fewer than 20 employees, you should file for both Part A and Part B on time.

How long does it take to get my Medicare card after I file?

Your card usually arrives in one to three weeks. Your coverage starts on your approval date, not when the card arrives, so you are covered when ready even if you have not received the physical card yet.