You can sign up for Medicare starting three months before your 65th birthday

Medicare enrollment opens on the first day of the month you turn 65, but you can actually start the process three months earlier. Your Initial Enrollment Period lasts seven months total: three months before the month you turn 65, the month you turn 65, and three months after. If you miss this window, you will pay a permanent penalty on your premiums for as long as you have Medicare — so the timing matters.

You do not have to wait until you turn 65 to begin. Many people sign up during the three-month window before their birthday because it gives them time to compare plans and understand their options without rushing. The Social Security Administration and Medicare.gov both let you start the process online or by phone well before your birthday arrives.

If you are still working and covered by your employer's health plan, different rules explore — you may be able to delay enrollment without penalty. This is called creditable coverage, and your employer's benefits office can tell you whether you may have access to.

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.
  • Signing up during the three months before your birthday gives you time to compare plans and understand your choices.
  • If you miss your Initial Enrollment Period, you will pay a permanent surcharge on your Part B and Part D premiums for each year you delayed.
  • If you have health coverage through your current job, you may be able to delay Medicare enrollment without penalty — ask your employer's benefits office.
  • You can sign up online through Medicare.gov, by phone at 1-800-MEDICARE, or in person at your local Social Security office.

What happens if you miss your Initial Enrollment Period

If you do not sign up during your seven-month window, you enter what Medicare calls a General Enrollment Period, which runs from January 1 to March 31 each year. You can sign up then, but coverage does not start until July 1 of that same year — a delay of several months. More importantly, you will owe a penalty.

The Part B premium penalty is 10 percent for each full year you were may be able to access but did not enroll. If you delayed for three years, your premium goes up 30 percent permanently — that increase stays with you for life, even after you turn 75 or older. The Part D prescription drug penalty works the same way: 1 percent of the national base premium for each month you were without coverage, compounded annually.

The only exception is if you had creditable coverage — health insurance through your job or a spouse's job that is at least as good as Medicare Part D. If you had creditable coverage, you can enroll without penalty during the General Enrollment Period or even later, as long as you enroll within 63 days of losing that coverage.

Special Enrollment Periods for life changes

If you experience certain life events, you may be able to enroll in Medicare outside the normal windows. These Special Enrollment Periods last 60 days and include losing employer coverage, moving to a new state, or having a major change in your health status. You must request the Special Enrollment Period yourself — Medicare does not automatically know about your situation.

Common may have access to events include retiring from a job where you had health coverage, losing coverage because your employer went out of business, or moving out of your current Medicare plan's service area. If you are turning 65 and losing employer coverage at the same time, your Initial Enrollment Period and the Special Enrollment Period run together, giving you more flexibility in timing.

To request a Special Enrollment Period, contact Medicare at 1-800-MEDICARE or visit Medicare.gov. Have your documentation ready — a letter from your employer showing your coverage ended, a notice from your insurance company, or proof of your move. Medicare will ask for specific evidence of the life change.

How to sign up during your enrollment period

You have three ways to enroll: online through Medicare.gov, by phone at 1-800-MEDICARE (1-800-633-4227), or in person at your local Social Security office. Online enrollment through Medicare.gov is usually the fastest — you can complete it in 15 to 20 minutes if you have your Social Security number and basic health history handy.

When you sign up, you will choose between Original Medicare (Part A and Part B) and a Medicare Advantage plan (Part C). You will also choose whether to add prescription drug coverage (Part D) and whether to add supplemental coverage (Medigap). These choices do not all have to be made on the same day, but making them during your Initial Enrollment Period avoids penalties.

If you sign up online, you will get a confirmation number when ready. If you call or visit in person, ask for written confirmation of your enrollment date. Keep this confirmation — it proves when you enrolled if there is ever a question about penalties or coverage start dates.

When coverage actually starts after you enroll

The month your coverage begins depends on when you enroll. If you enroll during the month you turn 65, your coverage starts on the first day of that month. If you enroll in the month before you turn 65, coverage starts the month you turn 65. If you enroll in the month after you turn 65, coverage starts the month after you enroll.

For example: if you turn 65 on June 15 and enroll in May, coverage starts June 1. If you enroll in June, coverage starts June 1. If you enroll in July, coverage starts August 1. This is why enrolling early matters — waiting until after your birthday month can delay your coverage start by a full month.

Once you enroll, you will receive your Medicare card in the mail within two to four weeks. You do not need the physical card to use your benefits — your coverage is active as soon as the start date arrives — but you will want it for your records and to show providers.

Enrollment periods for changing plans after your first year

After your Initial Enrollment Period ends, you get one chance each year to change your Medicare coverage. The Annual Enrollment Period runs from October 15 to December 7 each year. During this time, you can switch from Original Medicare to a Medicare Advantage plan, switch between Medicare Advantage plans, add or drop prescription drug coverage, or add or drop Medigap coverage.

Changes you make during the Annual Enrollment Period take effect January 1 of the following year. If you want your new coverage to start on January 1, you must enroll by December 7. Enrolling after December 7 means your new coverage will not start until the following month.

Outside the Annual Enrollment Period, you can only change plans if you have a may have access to life event — moving, losing coverage, or a major change in health status. These changes also trigger a 60-day Special Enrollment Period, just as they do for people turning 65.

Questions to ask your doctor or benefits counselor

Before you enroll, talk to your primary care doctor about which Medicare plan will work best for you. Ask whether your current doctors and hospitals are in-network for the plans you are considering, and whether your prescriptions are covered. Your doctor's office can usually answer these questions in one phone call.

You can also get free, unbiased counseling through your State Health Insurance information Program (SHIP). SHIP counselors are trained to explain your options and help you compare plans. To find your local SHIP, visit shiptalk.org or call 1-877-839-2675. This service is free and has no connection to any insurance company.

Frequently Asked Questions

What if I am still working at 65 — do I have to sign up for Medicare?

Not when ready. If you have health coverage through your current job, you can delay Medicare Part B without penalty as long as your employer has 20 or more employees. You must enroll within 63 days of retiring or losing that coverage. Ask your employer's benefits office whether your coverage counts as creditable coverage for Medicare purposes.

Can I change my mind after I enroll?

Yes, but only during specific windows. You have until the end of your Initial Enrollment Period to make changes without penalty. After that, you can only change plans during the Annual Enrollment Period (October 15 to December 7) or if you have a may have access to life event. Changes made outside these windows may not take effect until the following year.

What if my birthday is on the first of the month?

Your Initial Enrollment Period still runs three months before, the month of your birthday, and three months after. If your birthday is June 1, your enrollment period runs from March 1 to September 30. Your coverage will start June 1 if you enroll by June 30.

Do I need to enroll in all parts of Medicare at the same time?

No. You can enroll in Part A and Part B during your Initial Enrollment Period, then add Part D or Medigap later — but adding them later may trigger a penalty. It is simpler to make all your choices during your Initial Enrollment Period, even if you do not use all the coverage when ready.

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

You must be a U.S. citizen or permanent resident (green card holder) for at least five years to enroll in Medicare. If you are not yet a permanent resident, contact Medicare at 1-800-MEDICARE to discuss your situation. Some people on visas or temporary status may have other coverage options.