Medicare Part B covers doctor visits and outpatient care

Medicare Part B is the part of Medicare that pays for doctor office visits, lab tests, X-rays, ambulance services, and outpatient hospital care. It is not automatic — you have to sign up for it, and the timing matters because late sign-up penalties can add to your monthly premium for life.

Most people become may be able to access for Medicare at 65. If you are already getting Social Security benefits, Medicare will contact you automatically about three months before your 65th birthday. If you are not yet taking Social Security, you will need to sign up for Medicare yourself. The standard sign-up period is the three months before the month you turn 65, the month itself, and the three months after.

Part B has a monthly premium (the amount changes each year based on your income), and you pay a yearly deductible before Medicare starts to pay. You also pay a percentage of the cost for most services after that. The exact amounts depend on the service and whether you see a doctor who accepts Medicare.

Key Takeaways

  • You must sign up for Medicare Part B during your initial enrollment period — the three months before you turn 65, the month you turn 65, and the three months after — or face a permanent penalty on your premium.
  • If you are already receiving Social Security, Medicare will send you information automatically; if not, you must contact Social Security or Medicare yourself to sign up.
  • You can sign up online through Medicare.gov, by phone with Social Security, by mail, or in person at a Social Security office.
  • Part B has a monthly premium, a yearly deductible, and coinsurance costs, and the premium amount is based on your income from two years prior.
  • If you miss your initial enrollment period and do not have other health coverage, you may have to wait until the general enrollment period in January through March and will pay a higher premium.

When your initial enrollment period starts and ends

Your initial enrollment period is seven months long and centers on the month you turn 65. It begins three months before that birthday month and ends three months after. For example, if you turn 65 in June, your enrollment period runs from March through September.

During this window, you can sign up for Part B without penalty. If you sign up during the first three months (before your birthday month), coverage starts the month you turn 65. If you sign up in the month you turn 65 or after, coverage may be delayed by one or two months.

If you miss this seven-month window and do not have other may have access to health coverage, you will enter the general enrollment period, which runs January 1 through March 31 each year. Coverage would not start until July 1 of that year. You will also pay a permanent penalty — your monthly premium increases by 10 percent for each full 12-month period you were may be able to access but not signed up.

How to sign up online, by phone, or in person

The fastest way to sign up is online at Medicare.gov. Go to the sign-up section, create or log into your Medicare account, and follow the steps to enroll in Part B. You will need your Social Security number and information about any current health coverage. Online sign-up is available 24 hours a day.

You can also sign up by calling Social Security at 1-800-772-1213 (TTY 1-800-325-0778). Have your Social Security number ready. A representative will walk you through the enrollment process and answer questions about your coverage start date and premium amount. Wait times are often shorter early in the morning or on weekdays.

If you prefer to sign up in person, visit your local Social Security office. You can find the nearest office and hours on Social Security's website. Bring your Social Security card, proof of citizenship or legal residency, and proof of age (such as a birth certificate or passport). You do not need an appointment, but arriving early in the day usually means a shorter wait.

You can also sign up by mail. Call Social Security or visit Medicare.gov to request an enrollment form, fill it out, and mail it back. This method takes longer, so use it only if online, phone, or in-person sign-up is not possible.

What happens after you sign up

After you submit your enrollment, Medicare will send you a confirmation letter within two weeks. This letter shows your coverage start date and your monthly premium amount. Keep this letter — you may need it to show your doctor or insurance company that you have Part B coverage.

Your Medicare card will arrive in the mail before your coverage starts. The card shows your Medicare number (which is now your Social Security number followed by a letter) and which parts of Medicare you have. If you do not receive your card by the time coverage starts, you can still use the confirmation letter as proof of coverage.

Your monthly premium is deducted automatically from your Social Security check if you are receiving benefits. If you are not yet taking Social Security, Medicare will send you a bill each month. You can also set up automatic payments from your bank account through Medicare.gov.

Understanding Part B costs and what is covered

Part B has three types of costs: the monthly premium, the yearly deductible, and coinsurance. The monthly premium amount varies based on your income from two years before. For example, if you sign up in 2024, your premium is based on your 2022 income. Higher income means a higher premium.

Once you meet your yearly deductible (the amount changes each year), Medicare pays 80 percent of the cost for most services, and you pay 20 percent. Some services, like preventive care, have no deductible and no coinsurance — Medicare covers them in full. Other services, like mental health visits, may have different cost-sharing rules.

Part B does not cover everything. It does not cover routine dental care, vision exams for glasses, hearing aids, or long-term care. If you want coverage for these services, you can buy a supplemental insurance policy (called Medigap) or join a Medicare Advantage plan, which is an alternative to Original Medicare.

What to do if you missed your enrollment period

If you missed your initial enrollment period and did not have other health coverage during that time, you can still sign up, but you will face consequences. You will have to wait until the next general enrollment period (January 1 through March 31) to enroll, and your coverage will not start until July 1. Your monthly premium will be 10 percent higher for each full 12-month period you were may be able to access but not enrolled.

There are exceptions. If you had other health coverage — such as employer coverage, TRICARE, or Veterans benefits — you may not owe a penalty. You have eight months after that coverage ends to sign up for Part B without penalty. This is called a special enrollment period. You will need to prove you had the other coverage, so keep documentation like pay stubs showing employer insurance or a letter from your employer confirming coverage dates.

If you think you may have access to for a special enrollment period, contact Medicare at 1-800-MEDICARE (1-800-633-4227) to discuss your situation. They can review your coverage history and tell you whether you owe a penalty.

Questions to ask your doctor or Medicare

Before your coverage starts, ask your current doctor whether they accept Medicare and Medicare Part B specifically. Not all doctors do. You can also search for doctors who accept Medicare on Medicare.gov's provider search tool.

Ask Medicare or your doctor about whether you need a referral to see a specialist. Original Medicare does not require referrals, but some Medicare Advantage plans do. If you are considering a Medicare Advantage plan instead of Original Medicare with Part B, ask what the differences are in cost and coverage for the services you use most.

If you have questions about your premium amount or whether you may have access to for a premium subsidy based on income, call Medicare at 1-800-MEDICARE. They can explain your costs and tell you about programs that may help pay your premium if your income is low.

Frequently Asked Questions

What if I am still working at 65 and have employer health insurance?

You may not need to sign up for Part B right away. If your employer has 20 or more employees, you can delay Part B without penalty as long as you are covered by the employer plan. When you leave your job or lose the employer coverage, you have eight months to sign up for Part B without a late penalty. Tell Medicare about your employer coverage when you do sign up.

Can I change my mind after I sign up for Part B?

Yes, but only during certain times. If you sign up during your initial enrollment period, you can cancel Part B during the same enrollment period without penalty. If you want to cancel after that, you can do so during the general enrollment period (January through March), but you may owe a penalty if you drop it and later want it back.

Do I have to sign up for Part A at the same time as Part B?

Part A (hospital insurance) is usually automatic at 65 if you are receiving Social Security. You do not have to sign up separately. However, if you are not yet taking Social Security, you should sign up for both Part A and Part B at the same time to avoid missing important date and owing penalties.

What if my income changes after I sign up?

Your Part B premium is based on your income from two years prior. If your income drops significantly — such as after retirement or a major life change — you can contact Social Security to report the change and ask for a recalculation. You will need to provide documentation of your current income.

Is there a difference between signing up online and by phone?

No. Online, phone, and in-person sign-up all enroll you in the same Medicare Part B coverage with the same start date and premium. Choose whichever method is easiest for you. Online is fastest if you are comfortable with computers; phone is good if you have questions; in-person is best if you need help with documents.