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When Does Medicare Start? Navigating Eligibility, Enrollment, and More

Written by 
Molly Burford

Article at a glance

  • U.S. citizens are generally first eligible for health insurance coverage through Medicare around the age of 65. Younger Americans with ESRD or a disability may be eligible for Medicare earlier. 

  • There are various enrollment periods for Medicare when eligible Americans can sign up for their desired Medicare plan.

When preparing to retire, there are many factors that need to be considered. One of the most important is planning for healthcare coverage when no longer covered by an employer plan. For many Americans, this means signing up for Medicare. But when exactly does Medicare start? 

In general, many Americans will become eligible three months prior to the month they turn 65. However, there are certain cases in which someone may be eligible for coverage sooner, such as in the case of having a disability or end-stage renal disease (ESRD).

This article will explain everything there is to know about enrolling in Medicare, including how eligibility works, enrollment periods, and more.

What is Medicare?

Before answering the question of when Medicare coverage begins and how Medicare eligibility works, it is important to understand the Medicare basics.

Medicare is a federal government program that provides healthcare for adults over the age of 65 and for those under age 65 with certain disabilities. According to the Centers for Medicare and Medicaid Services (CMS), in 2019, over 61 million Americans were enrolled in Medicare.

The Federal Medicare Program is funded by Social Security, as well as Medicare income taxes. Those who worked for at least 10 years and paid Medicare taxes are eligible to sign up for Medicare at age 65 and receive Part A (hospital insurance) for free. Those who are younger than 65 but have received Social Security disability benefits for 24 months are also eligible for free Medicare Part A. 

Meanwhile, Part B (medical insurance) requires a monthly premium that is normally deducted from a beneficiary’s social security benefits or railroad retirement board benefits. It’s important to note that while most beneficiaries are automatically enrolled in Part A when they turn 65, they must enroll in Part B before the end of their initial enrollment period in order to avoid late enrollment penalties.

There are several ways to get Medicare coverage:

  • Original Medicare

  • Medicare supplement plans (Medicare Advantage, Dual Eligibles, Medigap)

Note: For more information on what Medicare is and whether or not you’re eligible, visit this source.

What is Original Medicare?

Original Medicare is comprised of Medicare Part A (hospital insurance) and Medicare Part B (medical insurance). Prescription drug coverage is not included under these Medicare Parts. Those interested in coverage for prescription drugs would need to enroll in a separate Medicare prescription drug plan known as Medicare Part D.

What are Medicare Supplement Insurance Plans?

A medicare supplement insurance plan helps bolster someone’s Medicare coverage to make it more comprehensive. There are a number of supplemental insurance plans Medicare enrollees can choose from.

What Is Medicare Advantage? 

Medicare Advantage plans, also known as Medicare Part C or MA plans, are supplemental Medicare plans. Medicare Advantage plans bundle Medicare Part A and Part B into one health insurance plan. MA plans are offered through private insurance companies that are Medicare-approved. 

Many Medicare Advantage plans also have additional benefits, including dental, hearing, and vision coverage. MA plans also often include Medicare Part D, prescription drug coverage, within its policies. 

Beneficiaries should always check with the plan’s insurance company to confirm extra health care benefits. They should also understand that the costs and expected out-of-pocket expenses will vary depending on the MA plan chosen.

What Is The Dual-Eligibles Program?

The Medicare-Medicaid Dual Eligibles program is for beneficiaries eligible for both Medicare benefits and Medicaid benefits. In this program, Medicare acts as the primary insurance while Medicaid acts as the secondary insurance.

What Are Medigap Plans? 

Medigap policies are another type of Medicare supplement insurance. Medigap is also known as MedSupp. Medigap policies are sold by private insurance companies and many help pay some out-of-pocket costs such as deductibles, coinsurance, and copays associated with Original Medicare coverage. 

When Does Medicare Start?

When Medicare coverage starts will depend on when an eligible person can sign up, which then determines which enrollment period they would be part of. Eligible persons for Medicare include:

  • Americans 65 and older

  • Americans 65 and younger with disabilities

  • Americans 65 and younger with end-stage renal disease (ESRD)

  • Spouses

Americans Age 65 (And Older)

In general, many Americans will first become eligible for Medicare three months before they turn 65. These enrollees would fall under the initial enrollment period (IEP), which lasts seven months.

Note: When the IEP begins for these enrollees depends on their actual birth date. Learn more about these timelines in the Medicare Initial Enrollment Period (IEP) section.

Americans With Disabilities

Americans with certain disabilities, such as Lou Gehrig’s disease, are eligible for Medicare sooner than age 65. Those receiving disability benefits from the Social Security Administration will automatically receive Medicare coverage within 24 months. 

Americans with ESRD

ESRD is the last stage of kidney failure. Those with ESRD do not need to wait until they turn 65 to be eligible for Medicare. That said, there all of the below criteria must be met in order to qualify: 

  • Their kidneys no longer work

  • They need routine dialysis or have had a kidney transplant

In addition to both of the aforementioned criteria being met, those with ESRD must also meet one of the following qualifications: 

  • They worked the required amount of time under Social Security, the Railroad Retirement Board (RRB), or as a government employee

  • They are already receiving, or are eligible for, either Railroad Retirement Board or Social Security retirement benefits 

  • They’re the spouse or dependent child of a person who meets either of the requirements listed above

Those eligible for Medicare due to ESRD should contact Social Security to see if they qualify. Those receiving RRB benefits should call 1–877-772‑5772.

Note: Learn more about ESRD Medicare coverage at this resource.

How to Enroll in Medicare

Once someone understands when they are eligible for Medicare, they will then need to confirm which enrollment period they are part of as well. There are three such periods when someone may be able to enroll in a Medicare plan: 

  • Initial Enrollment Period

  • General Enrollment Period

  • Special Enrollment Period

Medicare Initial Enrollment Period (IEP)

The first chance to enroll in Medicare for most Americans is during the Initial Enrollment Period (IEP). This enrollment period is specifically for those who are new to Medicare.

During this time, eligible persons have seven months to enroll in a Medicare plan. This seven-month period begins three months prior to their 65th birthday and ends three months from that date. This period includes their birthday month as well. 

In the event that a Medicare beneficiary has a birthday on the first of the month, their seven-month enrollment period will begin earlier. Instead, it will start four months prior to their 65th birthday, ending two months after the month they turn 65. 

During this period of time, most eligible persons are automatically enrolled in Medicare Part A. However, they must enroll in Part B during this timeframe to avoid a recurring late fee. Medicare Part B does require a monthly premium.

Medicare General Enrollment Period (GEP)

The General Enrollment Period is from January 1 to March 31 each year. For those who enroll during the general enrollment period, their coverage will begin on July 1. The General Enrollment Period is for those who missed their IEP.

Keep in mind, a monthly late enrollment penalty for Part B coverage may be administered if the enrollee didn’t qualify for a Special Enrollment Period. 

Medicare Special Enrollment Period (SEP)

There are special situations in which someone is able to enroll in Medicare Part B without paying a late enrollment penalty, despite missing the IEP. Do note, the SEP is only available for a limited time window in order to avoid the late enrollment penalty.

Qualifying events for SEP enrollment include: 

  • They are still working and have health insurance through their employer. This means they can sign up for Part A or Part B any time so long as:
    • They have group plan coverage
    • Either they, their spouse or another family member (if they have a disability) are working for an employer that provides health coverage

If an enrollee does not enroll during their specific Special Enrollment Period, they will need to wait for the next General Enrollment Period, which might mean paying a monthly late enrollment penalty for Part B coverage.

There are certain situations that do not qualify for the special enrollment period, such as:

  • COBRA coverage or retiree coverage ended: If an enrollee happens to miss their 8‑month sign-up period after they stopped working, they will have to wait for the next General Enrollment Period. 

  • They have (or lose) Marketplace coverage

  • They have ESRD: ESRD means different Medicare coverage timelines. (See above Americans With ESRD” section above.)

Note: Learn more about Special Enrollment Periods at this resource.

When Does Medicare Coverage Start?

Medicare coverage does not start the same date someone becomes eligible. It comes down to when someone signs up. For example, if someone signs up the month before they turn 65, their coverage starts their birthday month. If someone enrolls for Medicare the month they turn 65, then their coverage begins the following month. 

Note: Learn more about Medicare coverage and when it starts at this resource.

Tips for Navigating Medicare Enrollment

Navigating enrollment for Medicare can be confusing. Some tips for navigating through enrollment include: 

  • Contact a licensed health insurance agency: Talking to a licensed insurance agent can help answer any questions regarding health insurance.

  • Contact Medicare: Contacting the source directly can help get any confusion cleared up. Get contact information here.

How to Change Medicare Coverage

Medicare beneficiaries have the option to change their Medicare plan during Medicare Open Enrollment. Enrollees also have the option to add a standalone Part D plan or Medigap plan during this time. 

Open Enrollment is from October 15 to December 7 each year. Coverage will begin on January 1 as long as the plan gets the request by December 7.

Medicare Advantage also has an Open Enrollment Period, which lasts from January 1 to March 31 each year. This enrollment period is only available to those already enrolled in an MA plan. During this period, beneficiaries have the option to switch to a different Medicare Advantage Plan or switch to Original Medicare (and join a separate Medicare drug plan) once during this time. 

Note: Learn more about changing coverage at this resource.


Does Medicare start at 62?

No, while you may retire and receive Social Security benefits starting at age 62, you cannot enroll in Medicare until age 65 (unless you have a certain disability that makes you eligible earlier).

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