• Many people are automatically enrolled in original Medicare around their 65th birthday.
  • Others will need to manually enroll in all or some parts of Medicare.
  • The sign-up process starts 3 months before the month you turn 65, so take advantage of that enrollment window.

Medicare is the U.S. health insurance program for people 65 years old and over or those with certain health conditions. Applying for Medicare can seem like a rite of passage or a benchmark in a lifetime.

But signing up for Medicare can also be complicated. That’s because it has several parts, and you have to remember quite a few deadlines and enrollment periods. Plus, some people are automatically enrolled, while others are not.

The good news: The process is pretty streamlined and easy to maneuver. Here, we break down how you can apply for the various parts of Medicare and when you should begin.

Medicare is a federal health insurance program for adults who are 65 years old or over. Some people younger than that age may also qualify if they have certain disabilities. The various parts of Medicare each cover expenses related to hospital stays, doctor’s visits, prescription drugs, and more.

Most people will be eligible at age 65 for some or all parts of Medicare. It’s not required that you enroll exactly on your 65th birthday — but if you wait too long, you may end up paying late-enrollment penalties.

It’s important to understand how enrollment works, so you can make the right choices for your insurance needs. If you’re interested in coverage, it will be helpful to know the many parts of Medicare and what they cover:

  • Medicare Part A. Part A is hospital coverage, including inpatient stays, limited home health and skilled nursing facility care, and hospice care.
  • Medicare Part B. Part B is medical insurance for doctor’s visits, outpatient care, and other expenses like durable medical equipment.
  • Medicare Part C (Medicare Advantage). Part C offers all parts of original Medicare (parts A and B) through a private insurance company, usually with some extra benefits.
  • Medicare Part D. Part D is prescription drug coverage, offered through a private insurance company.
  • Medigap. Also known as Medicare supplement insurance, Medigap plans cover out-of-pocket expenses and “gaps” in original Medicare coverage.

American citizens and permanent residents are eligible for Medicare Part A around their 65th birthday. They may also elect to enroll in the other parts of Medicare at that time.

While the Centers for Medicare & Medicaid Services (CMS) is in charge of the Medicare health insurance program, you’ll apply for your coverage through the Social Security Administration (SSA).

The SSA will process your application. They can also help you with any questions related to enrollment.

If you’re receiving benefits from the SSA or the Railroad Retirement Board (RRB), you don’t have to apply for Medicare. You’ll automatically be signed up for Medicare parts A and B as you near your 65th birthday.

Your Medicare card and enrollment information will be mailed to you 3 to 4 months before your birthday. But if you’d like to enroll in Part D or want to switch to Medicare Advantage (Part C), you can do this during your initial enrollment period. We’ll explain more about that later.

If you’re not automatically enrolled, you’ll need to apply for original Medicare (parts A and B) and any additional coverage you want. Your enrollment period will depend on several factors, including your employment status and the types of coverage you want.

How to enroll in original Medicare

Before you begin the process of enrolling in Medicare parts A and B, you might consider what kind of Medicare coverage you ultimately need. These steps will help you prepare:

  1. Find out if you were automatically enrolled in either Part A or Part B of original Medicare.
  2. Decide whether you want Part B or if you’d like to defer enrollment.
  3. Review the Medicare Advantage plans in your area to see if those coverage options and costs work better for you than original Medicare.
  4. If you decide to stay with original Medicare, consider your Part D options and whether a Medigap plan would be useful to you.

The SSA provides a checklist for Medicare applications that may be helpful. It lists the types of forms you’ll need for the process, including proof of military service, tax forms, and W-2s. Once you have all the information you need for applying, you can begin the process of signing up.

You have several ways to enroll in original Medicare:

  • Online. You can visit SocialSecurity.gov to begin enrollment.
  • By phone. Call SSA at 800-772-1213 (or 800-325-0718 for TTY), Monday through Friday, 7 a.m. to 7 p.m.
  • In person. Visit your local SSA office; you can find it through the SSA office locator.
  • By mail. You can send a letter to your local SSA office with your name, your Social Security number, and the date you’d like to enroll. They will send you necessary information and any additional requests for enrolling.

If you already receive benefits from SSA or RRB, you’ll be automatically enrolled in Medicare. If you have questions or want to discuss your coverage, you can call RRB at 877-772-5772 (or 312-751-4701 for TTY), Monday through Friday, 9 a.m. to 3:30 p.m.

How to enroll in Medicare Part D

Enrollment in Medicare Part D is not automatic for anyone. If you decide you want prescription drug coverage, you’ll need to select and purchase a Medicare Part D plan.

It’s important to note that you can only get a Part D plan as an add-on to original Medicare (parts A and B). If you have Medicare Advantage (Part C), you aren’t eligible for a Part D plan.

You can enroll in Medicare Part D during your initial enrollment period, a 7-month window around your 65th birthday. If you don’t enroll during that time, you’ll be able to sign up later but may have to pay a late-enrollment penalty.

You may also be able to enroll during the open enrollment period, which is from October 15 through December 7.

If you want to enroll in Medicare Part D, you have several ways to do so:

  • By phone. You can call 800-633-4227 (or 877-486-2048 for TTY).
  • Online. Use Medicare.gov’s plan finder tool to compare Part D plans available in your area.
  • Contact a private insurance company. You can also contact private insurers that offer Part D plans, via their website or by phone, and enroll directly with them.

How to enroll in Medicare Advantage

Medicare Advantage, or Medicare Part C, is a private bundled health insurance plan. It offers the same coverage as parts A and B. If often provides prescription coverage as well. Some Medicare Advantage plans also cover vision, dental, and other healthcare benefits.

This plan may place a yearly cap on your out-of-pocket costs. That can be helpful if you expect to have any large healthcare expenses.

But a Medicare Advantage plan will be an additional cost on top of any premiums you pay for other parts of Medicare. Many Medicare Advantage plans will cover some or all of your Medicare Part B premium costs. Weigh your healthcare needs with the costs of coverage when deciding which parts of Medicare are right for you.

If you want to enroll in Medicare Advantage, you can sign up during your initial enrollment period. You can also change your selections during Medicare’s open enrollment period from October 15 through December 7. If you sign up outside these times, you may pay a late-enrollment fee, and your coverage won’t begin until July 1.

You have two ways to sign up for Medicare Part C:

  • Online. Shop for Part C plans with Medicare.gov’s plan finder tool.
  • With a private company. Insurance companies offer Part C plans, and you can enroll directly with them via their website or by phone.

If you’re planning to enroll in Medicare, you’ll need to know several enrollment deadlines and dates:

  • Initial enrollment period. This is a 7-month window around your 65th birthday during which you can sign up for Medicare. It begins 3 months before your birthday, includes the month of your birthday, and extends 3 months after your birthday. During this time, you can enroll for all parts of Medicare without a penalty.
  • Open enrollment period. Medicare’s open enrollment runs from October 15 to December 7. During this window, you can switch from original Medicare to Part C, or from Part C back to original Medicare. You can also switch Part C plans or add, remove, or change a Part D plan.
  • General enrollment period. This enrollment period runs yearly from January 1 through March 31. You can enroll in Medicare in this timeframe if you did not enroll during your initial enrollment period.
  • Special enrollment period. If you delayed Medicare enrollment because you had private health insurance from an employer, you can later enroll in Medicare during a special enrollment period. You have 8 months from the end of your coverage or the end of your employment during which to sign up without penalty.

Medicare Advantage also has a separate open enrollment period that runs from January 1 through March 31 each year. During this time, you can switch from one Part C plan to another or go back to original Medicare. But you can’t go from original Medicare to Part C during this period.

Your healthcare needs may change as you age, so make sure your Medicare coverage changes with you.

How can I check on my Medicare application?

If you applied for Medicare online, you can check the status of your application through your Medicare or Social Security account.

You can also check on your enrollment on Medicare.gov. You’ll be able to find information about your enrollment status by entering your:

  • ZIP code
  • Medicare number
  • last name
  • date of birth
  • Medicare Part A effective date

You can also check the status of your application by visiting or calling your local SSA office.

You don’t have to go through the enrollment process alone. Medicare and the SSA provide a number of free resources for people looking to sign up for Medicare. These resources include:

Several other enrollment counseling programs are available, but they may charge a fee. Ask about any costs up front before you agree to pay for this type of help. Free resources are available from the organizations above.

Applying for Medicare is an important step as you near your 65th birthday. It’s also one that can be filled with questions — but you don’t have to enroll alone.

Both the CMS and the SSA can be valuable resources during your enrollment period. They can help you make the right choices for your situation.

The information on this website may assist you in making personal decisions about insurance, but it is not intended to provide advice regarding the purchase or use of any insurance or insurance products. Healthline Media does not transact the business of insurance in any manner and is not licensed as an insurance company or producer in any U.S. jurisdiction. Healthline Media does not recommend or endorse any third parties that may transact the business of insurance.


Read this article in Spanish