Medicare Enrollment: Who, When, and How to Enroll

Fact Checked
Published: 12/16/2020
Contributing Expert: Ron Elledge
Reviewed by: Caren Lampitoc

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Ron Elledge
Medicare Consultant and Author
Ron Elledge
Medicare Consultant and Author

Ron Elledge is a seasoned Medicare consultant and author of “Medicare Made Easy.” As a Medicare expert, he regularly consults beneficiaries on Medicare rules, regulations, and strategies.

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Caren Lampitoc
Medicare Consultant
Caren Lampitoc
Medicare Consultant

Caren Lampitoc is an educator and Medicare consultant for Medicare Risk Adjustments and has over 25 years of experience working in the field of Medicine as a surgical coder, educator and consultant.

Timing is critical when enrolling and disenrolling in the various Parts and Plans of Medicare, and mistakes can be costly and nerve wracking. Gaining clarity and understanding will help you get the most out of this program.

Original Medicare is made up of Parts A and B. Part A is known as hospital insurance and helps cover inpatient hospital care, care in skilled nursing facilities, hospice care, and, under certain circumstances, home healthcare.

Part B is often referred to as “medical insurance”. It covers medical services received from a doctor and supplies that are medically necessary to treat your health condition. This can include outpatient care, diagnostic services, ambulance services, and durable medical equipment. It also covers some preventive services, including certain vaccines, cancer screenings, COVID-19 testing and treatments, rehabilitative services ordered by a doctor, and wellness visits.

Who Is Eligible for Medicare?

In general, you are eligible for Medicare if:

  • You are age 65 or older and a U.S. citizen or permanent legal resident for at least five consecutive years.
  • You are disabled and receiving disability benefits. Medicare is automatic after you have been on Social Security disability for 24 months.
  • You are already receiving retirement benefits from Social Security or Railroad Retirement benefits.
  • You were a state or local government employee after March 31, 1986, or a federal employee any time after December 31, 1982.
  • You have end-stage renal disease (ESRD) or Lou Gehrig’s disease (ALS).
  • You have been married to a qualified beneficiary for at least one year before applying.
  • You are divorced from a qualified beneficiary whom you were married to for a minimum of 10 years, and you are single at the time of application.
  • You are widowed by a qualified beneficiary to whom you were married for at least nine months before their death, and you are single at the time of application.

If you do not qualify under these requirements, you may be able to purchase Part A and enroll in Part B. Contact Social Security with any questions about this at or 1-800-772-1213.

When Should I Enroll?

Parts A and B can be enrolled in together simultaneously or at separate times. The standard enrollment period is known as the Initial Enrollment Period (IEP). It is a seven-month period beginning three months prior to the month in which you turn 65, the month in which you turn 65, and the three months after turning 65. Example, if you turn 65 on May 14, your IEP will run from February 1 through August 31.

The first three months of your IEP are the optimal months in which to enroll. In this example, if enrollment occurs during Feb., March, or April, your Medicare will begin on May 1. If you enroll in May, your coverage begins June 1. However, in order to push for promptness in enrollment, the later you enroll the longer you wait for coverage. If you enroll in June, your coverage will begin August 1; if enrollment is in July your coverage begins October 1; and if in August, your coverage begins November 1. Keep in mind that to enroll in either a Medicare Supplement Plan (Medigap), or a Medicare Advantage Plan, you must be enrolled in both Part A and Part B of Original Medicare.

Part A Enrollment: Most people enroll in Part A during their IEP because, if you have worked and paid taxes for 40 quarters in your lifetime, Part A is premium-free. The main reason some defer Part A is because of a Health Savings Account (HSA). Since HSAs include a high deductible insurance plan, you cannot be enrolled in it at the same time as Medicare. Contributions to an HSA should be stopped six months prior to enrolling in any part of Medicare. However, once you are in Medicare, you may continue to draw from the assets in the HSA.

Part B Enrollment: In most cases, you should also enroll in Part B during your IEP. However, there are two Special Enrollment Periods (SEPs) which enable you to defer Part B without later encountering Part B Late Enrollment Penalties or a delayed start to coverage. The first is for those who will have creditable employer health insurance coverage through either their own or their spouse’s employer. If you will have continuous employer coverage, you may defer Part B and you will have a one-time SEP when you either lose your creditable coverage or leave the employer. This SEP begins when coverage or employment ends and it continues for eight months. During this period, you can enroll in Original Medicare and Supplemental or Advantage Plan coverage. CAUTION: COBRA and Retirement Plans do not count as creditable coverage; you must be covered under a current employer plan.

The second SEP is for those who will be volunteering for a nonprofit charitable organization while overseas. It must be a US tax exempt organization and you must remain overseas a minimum of 12 months. You must also maintain health coverage through either the organization or the country in which you are volunteering. If you do not qualify for one of these two exemptions, you will most likely be subject to financial penalties when enrolling in Part B later. Late Part B filers may only enroll during the General Election Period which runs from January 1 through March 31 of each year, with coverage beginning July 1. This may delay coverage for up to 15 months.

How do I Enroll in Medicare?

If you are turning 65 and you receive Social Security Administration (SSA) or Railroad Retirement Board (RRB) benefits, or you are a state, local, or federal government worker (including American Foreign Service workers), enrollment in Original Medicare (Parts A and B) should be  automatic when you turn 65. Your Medicare benefits usually start on the first day of your birthday month.

If you are not automatically enrolled in Part A and Part B, contact Social Security or the RRB during the three months before you turn 65 — the earlier, the better. I suggest that everyone should make this contact three months before turning 65 and confirm that everything is in order.

The easiest way to initiate the Medicare enrollment process is with a simple phone call to the Social Security Administration at 1-800-772-1213 who handles enrollment.

If Social Security enrolls you over the phone, ask for the Medicare number assigned to you, the start dates for both A and B, and when you can expect your card in the mail. If you do not receive the card when promised, follow up on it. When you do receive your card, make sure your name is spelled correctly and verify that the Medicare number is the same. Also confirm the card shows the correct start dates for Parts A and B. If you are required to appear in person at the Social Security office, ask what information you need to bring with you and be prompt for your appointment.

You may also open an account by logging on to the Social Security website at

Whichever way you initiate contact with the SSA, do it early and keep track of your conversations. Be sure to log the date, the time, and the name of the person you talk with, as well as any pertinent information. Because of the importance of having Medicare business conducted in a timely manner, and the volume of cases handled by their agents, it is important to keep records in the event a mistake is made in the processing of your enrollment.

Learn More About Medicare Enrollment