When and How to Sign Up for Medicare

You can sign up for Medicare starting three months before the month you turn 65. The Social Security Administration handles most enrollments automatically if you are already receiving Social Security benefits, but you still need to confirm your coverage choices. If you are not yet on Social Security, you must sign up yourself through Medicare.gov, by phone, or in person at a Social Security office.

Your initial enrollment period lasts seven months: three months before your 65th birthday month, the month itself, and three months after. Missing this window can mean paying a permanent penalty on your premiums, even if you sign up years later. The penalty is 10 percent of the standard Part B premium for each full year you were may be able to access but did not enroll.

If you are still working and have health insurance through your employer, you may be able to delay Part B enrollment without penalty, but you must file a form called the process for Enrollment in Part B (CMS-40B) to document this exception. Do not assume your employer plan counts as coverage — some plans do not, and the Social Security office can tell you whether yours does.

Key Takeaways

  • You can enroll starting three months before you turn 65, and your enrollment window stays open for seven months total.
  • If you receive Social Security, Medicare enrollment happens automatically, but you must choose between Original Medicare and Medicare Advantage and select a drug plan.
  • Signing up late for Part B or Part D (prescription drug coverage) triggers permanent penalties unless you have employer coverage or other may have access to circumstances.
  • You can change your coverage choices during the Annual Enrollment Period (October 15 to December 7 each year) or if you experience a may have access to life event.
  • The three main enrollment routes are online at Medicare.gov, by phone at 1-800-MEDICARE, or in person at your local Social Security office.

Documents and Information You Will Need

Gather these items before you start the enrollment process. You will need your Social Security number, date of birth, and citizenship or immigration status. Have your current health insurance information on hand — the name of your plan, policy number, and group number if applicable.

If you are enrolling in a Medicare Advantage plan or a prescription drug plan, you will also need to know which doctors and pharmacies you use, because different plans cover different providers. Check your current prescriptions and bring a list of the medications you take, including the dose and how often you take them. This helps you compare drug plans and see which one covers your medications at the lowest cost.

If you are not yet receiving Social Security, bring proof of age (birth certificate, passport, or driver's license), proof of citizenship or legal residency (passport, naturalization papers, or green card), and your state ID or driver's license. You will also need to set up a Medicare.gov account, which requires an email address and a password you create.

Enrolling Online Through Medicare.gov

Go to Medicare.gov and select "Sign Up for Medicare" at the top of the page. You will be asked whether you are signing up for the first time, already have Medicare, or are helping someone else. Choose "Sign up for the first time" and enter your name, date of birth, and Social Security number.

The site will ask you to create a login account if you do not already have one. Use an email address you check regularly and a strong password. After you log in, you will answer questions about your citizenship, whether you are a federal employee, and whether you have other health coverage. Answer honestly — these answers determine which parts of Medicare you can enroll in and whether you face penalties.

Next, you will choose your coverage. Medicare has two main paths: Original Medicare (Part A for hospital care and Part B for doctor visits) plus a separate prescription drug plan, or Medicare Advantage (Part C), which is an all-in-one plan run by a private insurance company that includes hospital, doctor, and usually drug coverage. Medicare.gov shows you plans available in your zip code, their monthly premiums, and which doctors and pharmacies they cover. Review the plan details carefully before confirming your choices.

After you submit your enrollment, you will receive a confirmation number. Save this number and the confirmation email. Your coverage typically begins on the first day of the month after you enroll, though if you enroll during your initial enrollment period, your coverage may begin on the first day of the month you turn 65.

Signing Up by Phone or In Person

Call 1-800-MEDICARE (1-800-633-4227) to enroll over the phone. The line is open Monday through Friday, 8 a.m. to 8 p.m. Eastern time. Have your Social Security number, date of birth, and current insurance information ready. A representative will walk you through your coverage choices and answer questions about costs and coverage.

You can also visit your local Social Security office in person. Find the nearest office at ssa.gov or call 1-800-772-1213. Bring your Social Security card, proof of citizenship or legal residency, and your state ID or driver's license. An agent will help you complete the enrollment forms and answer questions about your options. In-person appointments often have shorter wait times if you call ahead and schedule one.

If you are deaf or hard of hearing, call 1-877-486-2048 (TTY). If you speak a language other than English, Medicare provides free interpreters on the phone line — tell the representative your language when you call.

Understanding Your Coverage Start Date and First Premium Payment

Your coverage start date depends on when you enroll. If you enroll during your initial enrollment period (the seven months centered on your 65th birthday), your coverage begins on the first day of the month you turn 65, regardless of when in that month you sign up. If you enroll after your initial period ends, your coverage begins the first day of the month after you complete enrollment.

Your first premium payment is usually deducted from your Social Security check if you receive benefits. If you do not receive Social Security, Medicare will send you a bill. Part A (hospital insurance) has no monthly premium for most people, but Part B has a standard premium that varies by income. In 2024, the standard Part B premium is $164.90 per month, but higher-income beneficiaries pay more. Medicare Advantage and prescription drug plans have their own premiums, which vary by plan and location.

You will receive your Medicare card in the mail within two weeks of enrollment. Your card shows your Medicare number, which you will use to identify yourself at doctor's offices and pharmacies. Do not wait for the card to arrive before your coverage begins — your coverage is active on your start date even if you have not received the physical card yet.

Special Enrollment Periods and Life Changes

If you miss your initial enrollment period, you may still be able to sign up without penalty during a Special Enrollment Period if you experienced a may have access to life event. These events include losing employer health coverage, moving to a new state, getting married or divorced, or having a significant change in income.

You also have an Annual Enrollment Period every year from October 15 to December 7. During this time, you can switch from Original Medicare to Medicare Advantage, from Medicare Advantage to Original Medicare, or change your prescription drug plan. Changes made during the Annual Enrollment Period take effect January 1 of the following year.

If you experience a may have access to life event outside the Annual Enrollment Period, you have 60 days from the event to make changes. may have access to events include losing or gaining health coverage, moving out of your plan's service area, or having a change in your family status. Contact Medicare at 1-800-MEDICARE to report the event and learn whether you can make changes.

Common Mistakes to Avoid

Do not assume Social Security will automatically enroll you in Part B. If you are not yet receiving Social Security when you turn 65, you must sign up for Medicare yourself, or you will face a late-enrollment penalty. Even if you receive Social Security, you still need to choose between Original Medicare and Medicare Advantage and select a prescription drug plan — Social Security does not make these choices for you.

Do not skip Part D (prescription drug coverage) if you take medications. If you go without drug coverage for more than 63 days in a row, you will pay a permanent penalty when you finally enroll. The penalty is 1 percent of the national average drug plan premium for each month you were without coverage, and it applies for as long as you have Medicare.

Do not ignore your plan's formulary — the list of medications it covers. A plan may have a low premium but not cover the drugs you need, or it may cover them only at a high cost-sharing level. Compare drug plans using the plan finder on Medicare.gov, which shows you the out-of-pocket cost for your specific medications under each plan.

Do not assume your current doctor accepts Medicare. Before you enroll in a plan, check whether your doctors and specialists are in the plan's network. If your doctor is not in the network, you may have to pay more or switch providers. Medicare.gov's plan finder lets you search by doctor name to see which plans include them.

Frequently Asked Questions

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

You can delay Part B enrollment without penalty if your employer has 20 or more employees and you are covered under the employer's plan. You must file form CMS-40B to document this exception. When you leave your job or lose the coverage, you have eight months to enroll in Part B without penalty. If you do not file the form, you will be charged a penalty even though you had coverage.

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 change your choices. After that, you can make changes only during the Annual Enrollment Period (October 15 to December 7) or if you experience a may have access to life event. Outside these windows, your choices are locked in for the year.

What is the difference between Original Medicare and Medicare Advantage?

Original Medicare is run by the federal government and covers hospital care (Part A) and doctor visits (Part B) at any provider that accepts Medicare nationwide. You pay a deductible and coinsurance for each service. Medicare Advantage is run by private insurance companies and bundles hospital, doctor, and usually drug coverage into one plan with a monthly premium, but you must use doctors and hospitals in the plan's network.

Do I have to pay for Part A?

Most people do not pay a monthly premium for Part A if they or their spouse paid Medicare taxes for at least 10 years while working. If you do not meet this requirement, you may be able to buy Part A coverage, but the premium can be high. Contact Social Security to find out whether you may have access to for premium-free Part A.

What happens if I enroll late?

You will pay a permanent penalty on your Part B and Part D premiums for as long as you have Medicare. The Part B penalty is 10 percent of the standard premium for each full year you were may be able to access but did not enroll. The Part D penalty is 1 percent of the national average drug plan premium for each month you were without coverage. These penalties do not go away even if you move to a different plan.