You can enroll in Medicare starting three months before you turn 65

Medicare enrollment opens on the first day of the month you turn 65, but you can sign up as early as three months before that birthday. The enrollment window stays open for seven months total — three months before, the month you turn 65, and three months after. If you miss this window, you may pay a penalty for the rest of your life, so marking your calendar now is worth the five minutes it takes.

You do not have to wait until your birthday month to act. Many people enroll during the three-month window before they turn 65 because it gives them time to compare plans and ask questions without rushing. Your coverage will start on the first day of the month you turn 65, no matter when during the window you sign up.

Key Takeaways

  • You can enroll in Medicare starting three months before you turn 65, and you have until three months after your birthday to sign up without penalty.
  • You can enroll online at Medicare.gov, by phone at 1-800-MEDICARE, or in person at your local Social Security office.
  • Part A (hospital insurance) and Part B (doctor visits) are the foundation of Medicare, and most people pay a monthly premium for Part B.
  • If you are still working and covered by your employer's health plan, you may be able to delay Part B enrollment without penalty.
  • Once you enroll, your Medicare card will arrive in the mail within two weeks, and coverage begins on the first day of the month you turn 65.

Where to enroll in Medicare

You have three main ways to enroll: online, by phone, or in person. The online route is the fastest — go to Medicare.gov, click "Sign Up for Medicare," and follow the steps. You will need your Social Security number and information about any current health coverage you have. The whole process takes about 10 minutes.

If you prefer to talk to someone, call 1-800-MEDICARE (1-800-633-4227). Representatives are available Monday through Friday, 8 a.m. to 8 p.m. Eastern time, and they speak multiple languages. You can also visit your local Social Security office in person — find the nearest one at ssa.gov/locator.

What Part A and Part B cover

Part A is hospital insurance. It covers inpatient hospital stays, skilled nursing facility care after a hospital stay, hospice care, and some home health services. Most people do not pay a monthly premium for Part A because they or their spouse paid Medicare taxes while working. You will pay a deductible when you use it — currently $1,676 per hospital stay, though this amount changes each year.

Part B is medical insurance for doctor visits, outpatient care, lab tests, and preventive services. Part B requires a monthly premium, which is based on your income. In 2024, the standard premium is $164.90 per month, but you may pay more or less depending on your income from two years ago. Part B also has a yearly deductible — currently $240 — and you pay 20 percent of most services after you meet it.

When you enroll in Medicare, you are automatically enrolled in Part A. Part B enrollment is optional, but if you do not sign up when you are first may be able to access and you do not have other may have access to coverage, you will pay a 10 percent penalty on your Part B premium for each year you delayed. That penalty stays with you for life.

When you can delay Part B without penalty

If you are still working at age 65 and your employer has 20 or more employees, you can delay Part B enrollment without penalty. Your employer's health plan is considered "creditable coverage," which means it meets Medicare's standards. You have eight months after you leave your job or lose that coverage to enroll in Part B without penalty.

This rule applies only to Part B, not Part A. You should still enroll in Part A at 65 because it has no premium and no penalty for delaying, so there is no reason to wait. If you are self-employed or your employer has fewer than 20 employees, you cannot use this exception — you should enroll in Part B at 65 to avoid the penalty.

What happens after you enroll

Once you submit your enrollment, you will receive a confirmation number. Keep this for your records. Your Medicare card will arrive in the mail within two weeks, though it may take longer during busy periods. Your coverage starts on the first day of the month you turn 65, even if your card has not arrived yet.

When your card arrives, check it for errors — your name, date of birth, and Medicare number should all be correct. If something is wrong, call 1-800-MEDICARE to report it. Do not use your card until you have verified the information, because mistakes can cause claims to be denied.

Choosing between Original Medicare and Medicare Advantage

When you enroll in Part A and Part B, you are choosing Original Medicare, which is run by the federal government. You can see any doctor or hospital that accepts Medicare, and you have freedom to change doctors whenever you want. However, Original Medicare does not cover prescription drugs or dental care, and you are responsible for 20 percent of most costs after you meet your deductible.

Medicare Advantage (Part C) is an alternative offered by private insurance companies. It includes all the benefits of Part A and Part B, plus usually prescription drug coverage, dental, and vision. However, you must use doctors and hospitals in the plan's network, and you may need approval before certain services. If you choose Medicare Advantage, you do not enroll in Part B separately — the Advantage plan replaces it.

You do not have to decide between Original Medicare and Medicare Advantage when you first enroll. You can choose Original Medicare now and switch to Medicare Advantage later during the annual enrollment period (October 15 to December 7 each year). However, if you wait to enroll in Part B, you may face a penalty, so it is safer to enroll in Part B at 65 even if you are leaning toward Medicare Advantage.

Adding prescription drug coverage

If you choose Original Medicare, you need to enroll in Part D (prescription drug coverage) separately. You can enroll in Part D when you enroll in Medicare at 65, or during the annual enrollment period. If you do not enroll in Part D when you first become may be able to access and you do not have other may have access to drug coverage, you will pay a penalty for each month you go without it — the penalty is added to your Part D premium permanently.

Part D plans vary widely in cost and which drugs they cover. You can compare plans at Medicare.gov by entering your zip code and the medications you take. Plans are ranked by estimated yearly cost, so you can see which one will be cheapest for your specific situation. If your circumstances change — you move, your medications change, or your income changes — you can switch Part D plans during the annual enrollment period.

Frequently Asked Questions

What if I turn 65 but I am not a U.S. citizen?

You must be a U.S. citizen or a permanent resident who has lived in the United States for at least five consecutive years to be may be able to access for Medicare. If you are a permanent resident, bring your green card when you enroll. If you are not yet a permanent resident, you cannot enroll in Medicare.

Do I have to enroll in Medicare if I am still working?

You do not have to enroll in Part B if you are covered by your employer's health plan and your employer has 20 or more employees. However, you should enroll in Part A because it has no premium and no penalty for delaying. If your employer has fewer than 20 employees, you should enroll in both Part A and Part B at 65 to avoid the Part B penalty.

What if I miss the seven-month enrollment window?

You can still enroll in Medicare after the window closes, but you will likely pay a penalty. For Part B, the penalty is 10 percent of the standard premium for each year you delayed, and it stays on your premium for life. You can enroll during the General Enrollment Period (January 1 to March 31 each year), and coverage will start July 1.

Can I change my mind after I enroll?

Yes. You have a trial period of 12 months to try Original Medicare or Medicare Advantage and switch between them without penalty. After 12 months, you can still switch during the annual enrollment period (October 15 to December 7), but you may face waiting periods or coverage limits if you switch back and forth.

How much will Medicare cost me each month?

Part A has no monthly premium for most people. Part B costs between $164.90 and $560.50 per month in 2024, depending on your income. If you choose Medicare Advantage or add Part D, those have their own premiums that vary by plan. You can see estimated costs for specific plans at Medicare.gov.