You must sign up for Medicare during specific windows, or you will pay a penalty for as long as you have coverage

Medicare enrollment is not automatic. You have to register yourself, and the timing matters. If you miss your window, you will owe a late enrollment penalty — a permanent increase to your monthly premium that stays with you for life, even if you sign up years later. The penalty grows the longer you wait.

The main enrollment period is three months before, the month of, and three months after your 65th birthday. This seven-month window is your best chance to sign up without penalty. If you are already receiving Social Security, Medicare will contact you automatically about three months before your 65th birthday. If you are not yet receiving Social Security, you must contact Medicare yourself or register online.

There are other enrollment periods for people in specific situations — those still working past 65, those losing employer coverage, those moving to a new state. Each has its own rules and important date. Missing the important date that applies to you can be expensive.

Key Takeaways

  • Your main enrollment window is seven months long: three months before your 65th birthday, the month you turn 65, and three months after.
  • If you miss this window and do not have a may have access to reason, you will pay a permanent penalty on top of your regular Medicare premium.
  • People still working at 65 with employer health insurance have a different important date and should not sign up during the regular window.
  • You can register online at Medicare.gov, by phone at 1-800-MEDICARE, or in person at your local Social Security office.
  • If you miss your important date but have a may have access to life event, you may have a second chance during a Special Enrollment Period.

The seven-month window around your 65th birthday

This is the standard enrollment period, and it is your widest opportunity. It runs from the first day of the third month before you turn 65 through the last day of the third month after your birthday. For example, if you turn 65 in June, your window opens on March 1 and closes on September 30.

During this window, you can sign up for Medicare Part A (hospital insurance), Part B (medical insurance), and Part D (prescription drug coverage) without penalty. You can also choose between Original Medicare and a Medicare Advantage plan. If you sign up by the last day of the month you turn 65, your coverage starts the first day of the following month. If you sign up after that, your coverage will be delayed.

If you are already receiving Social Security retirement benefits, the Social Security Administration will send you information about Medicare enrollment automatically. You do not have to do anything if you want to accept the default enrollment. However, you should review what is being offered — the default may not be the best choice for your situation.

What happens if you miss the important date

A late enrollment penalty is added to your Part B and Part D premiums if you do not sign up during your initial enrollment period and do not have a may have access to reason for the delay. The penalty is calculated as a percentage of the national average premium for each part, multiplied by the number of months you were not enrolled. This penalty is permanent — it does not go away even after you finally sign up.

For Part B, the penalty is 10 percent of the national average premium for each full month you were not enrolled. For Part D, it is 1 percent of the national average premium for each month of delay. These amounts change each year, so the exact dollar amount of your penalty depends on when you sign up and what the current premiums are.

The penalty applies every month you have Medicare, for the rest of your life. If you wait five years to sign up, you will pay a penalty for five years' worth of months. There is no way to remove this penalty once it is applied, even if you later change your mind about Medicare or switch plans.

Special enrollment periods for people still working

If you are still working at 65 and your employer offers health insurance, you do not have to sign up for Medicare during your regular enrollment window. Instead, you can use your employer coverage and delay Medicare enrollment without penalty. This is called creditable coverage, and it means your employer plan is considered as good as or better than Medicare.

When you leave your job or lose your employer coverage, you have eight months to sign up for Medicare without penalty. This eight-month window is called a Special Enrollment Period. It starts the month after your employment ends or your coverage ends, whichever is later. You must sign up during this window to avoid a late enrollment penalty.

You will need to prove that you had employer coverage. Your employer or the plan administrator can provide a letter stating the dates you were covered and confirming that the plan meets Medicare's standards for creditable coverage. Keep this letter — you may need it if Medicare questions why you did not sign up at 65.

Other may have access to events that give you a second chance

If you miss your regular enrollment window but experience certain life changes, you may be able to sign up during a Special Enrollment Period without penalty. These may have access to events include losing employer coverage, moving out of your Medicare Advantage plan's service area, losing Medicaid, or having your plan drop out of Medicare.

You have 60 days from the date of the may have access to event to sign up. The coverage start date depends on when you sign up and what type of coverage you choose. For example, if you lose employer coverage on June 15 and sign up for Medicare on July 10, your coverage might start on August 1.

You will need to provide proof of the may have access to event. This might be a letter from your employer, a notice from your insurance company, or a document from Medicaid. Medicare will ask for this proof when you sign up, so gather it before you contact them.

How to register for Medicare

You can sign up online, by phone, or in person. The online method is usually fastest. Go to Medicare.gov and click "Sign up for Medicare." You will need your Social Security number, date of birth, and citizenship information. The process takes about 10 minutes, and you will get a confirmation number right away.

If you prefer to call, dial 1-800-MEDICARE (1-800-633-4227). Representatives are available Monday through Friday, 8 a.m. to 8 p.m. Eastern time. Have your Social Security number and date of birth ready. The call usually takes 15 to 20 minutes.

You can also visit your local Social Security office in person. Bring your Social Security card, proof of citizenship (a birth certificate, passport, or naturalization papers), and proof of residence (a utility bill or lease). The office will help you complete the enrollment form and answer questions about your options.

What to ask your doctor before you sign up

Before you choose a Medicare plan, talk to your primary care doctor and any specialists you see regularly. Ask whether they accept Medicare, and specifically whether they accept Original Medicare or only certain Medicare Advantage plans. If you have prescriptions, ask your pharmacy which Medicare Part D plans they work with.

If you have a chronic condition that requires ongoing treatment, ask your doctor which plan would work best for your care. Some Medicare Advantage plans have different rules about referrals, prior authorization, and out-of-pocket costs. Your doctor can help you understand how these rules might affect your treatment.

When to contact Medicare if something goes wrong

If you believe you have a may have access to reason for missing your enrollment important date, contact Medicare as soon as possible. Do not wait — the sooner you explain your situation, the sooner Medicare can determine whether you may have access to for a Special Enrollment Period. You can call 1-800-MEDICARE or visit your local Social Security office.

If you signed up late and were charged a penalty, you can ask Medicare to reconsider. This is called a reconsideration request. You must have a good reason — for example, Medicare gave you incorrect information, or you were unable to sign up due to a serious illness. Submit your request in writing to the address Medicare provides, along with any documents that support your case.

Frequently Asked Questions

What if I turn 65 while I am still working?

You do not have to sign up for Medicare at 65 if your employer offers health insurance and you are still actively working. You can delay enrollment and sign up later when you retire or lose your coverage, without paying a penalty. Tell your employer's benefits office that you are declining Medicare so they know you have made an informed choice.

Can I sign up for Medicare before I turn 65?

No. Your enrollment window opens three months before your 65th birthday, not before. If you try to sign up earlier, your process will be rejected. Mark your calendar for the first day of the third month before your birthday so you do not forget.

What if I was not told about Medicare and missed my important date?

Contact Medicare when ready and explain what happened. If Medicare failed to send you required notices or gave you wrong information, you may may have access to for a Special Enrollment Period. You will need to provide evidence — for example, a returned piece of mail or a record of a call to Medicare. Submit a written reconsideration request with any supporting documents.

Do I have to sign up for Part D prescription drug coverage at 65?

You do not have to, but if you go without Part D coverage and later sign up, you will owe a late enrollment penalty unless you had creditable coverage from another source. Even if you do not take prescriptions now, signing up during your initial window protects you from future penalties.

What if I move to a different state after I turn 65?

If you move and your Medicare Advantage plan does not serve your new area, you have two months from the move to switch to a different plan or to Original Medicare without penalty. Contact Medicare with your new address so they can tell you which plans are available in your new location.