When Does Medicare Coverage Start?

If you get your health insurance through your employer, you’re likely familiar with the open enrollment periods when you must choose your coverage for the coming year. Similarly, when it’s time to sign up for Medicare, you can do so during certain enrollment periods under specific circumstances.

Here’s what you should know about the right time to sign up for Medicare, when coverage starts, how to enroll, and the potential consequences of enrolling late.

When does Medicare start?

Medicare typically begins at age 65, but certain cases allow for earlier enrollment. For example, some exceptions include disability, end-stage renal disease (ESRD), and Lou Gehrig’s disease (also known as amyotrophic lateral sclerosis, or ALS).^[1]

When does Medicare open enrollment start?

Medicare has several different enrollment periods, similar to insurance provided by an employer group health plan. These are specific times when you can sign up for Medicare.

Initial enrollment period

The initial enrollment period is the first chance you’ll get to sign up for Medicare. The period starts three months before you hit age 65, includes your birthday month, and ends three months after it. In total, it lasts seven months.

So, if you’re near 65, you can use this time to sign up for Part A and Part B. When Medicare starts will depend on when you signed up, but coverage begins the first day of the month.

General enrollment period

The general enrollment period starts Jan. 1 and ends March 31 every year. After signing up for Medicare, your coverage kicks in the following month.

This is the time to sign up for Medicare Part A and Part B if you’ve missed the initial enrollment period or don’t qualify for a special enrollment period, according to the National Council on Aging.

Special enrollment period

The special enrollment period is available in special circumstances and lasts for a limited time. This is typically for people who’ve missed the initial enrollment period for good reason and need to sign up for Part A and Part B.

Some events that qualify include:

• Losing your Medicaid coverage

• Being affected by a natural disaster

• Received inaccurate information from your employer or health plan

• Incarceration

• Exceptional conditions (must contact local Social Security office for approval)

• Having or previously having health coverage through an employer or spouse

• Volunteering in a foreign country

• Having TRICARE

People who are eligible can sign up for Medicare and avoid any late-enrollment penalties.^[2]

People with disabilities

People with certain conditions and disabilities may be eligible for Medicare coverage Part A and B before the age of 65. Qualifying conditions include:

• People who’ve received 24 months of Social Security Disability Insurance (SSDI) benefits will get Medicare coverage on the 25th month

• Lou Gehrig’s disease, also called ALS

• End-stage renal disease (ESRD)

The parts of Medicare and what each covers

Medicare has multiple “parts,” and each covers something different. It’s important to understand the parts of Medicare so you can enroll for the coverage you need during the appropriate enrollment window.

Part A: Hospital insurance

Medicare Part A is hospital insurance and covers:

• Inpatient hospital care

• Home healthcare

• Nursing facility care

• Hospice care

Most people pay nothing for Part A coverage, provided they meet eligibility requirements. Generally, you’ll qualify for free Part A if you or a spouse worked and paid Medicare taxes for at least 10 years.^[3]

If you don’t qualify for premium-free Part A, the current premium cost will be $278 or $505 per month, depending on how long you (or your spouse) worked and paid Medicare taxes.

Part B: Medical insurance

Medicare Part B is medical insurance that covers:

• Services you receive from doctors or another healthcare provider

• Preventative services like screenings and vaccines

• Medical equipment such as wheelchairs

• Home healthcare

• Outpatient care

Part B’s premium can change every year. In 2024, the standard premium is $174.70 per month. The Part B premium can be higher depending on your income and tax filing status.

Currently, Part B has an annual deductible of $240. After you meet your deductible — which is how much you pay before your benefits start — you’ll typically pay 20% for each service. Medicare Part A and Part B make up what’s called Original Medicare.

Part C: Medicare Advantage

Medicare Part C is also known as Medicare Advantage. Part C generally includes Parts A and B, and Part D (prescription drug coverage) together through a private, Medicare-approved insurer.

In some cases, Medicare Advantage policies have lower out-of-pocket costs and provide additional benefits, such as dental or vision services. The premiums and deductibles you pay for Part C vary by insurer.

Part D: Prescription drug coverage

Medicare Part D includes prescription drug coverage. You can get Part D as an add-on to Original Medicare, which is Part A and Part B, or through Part C, Medicare Advantage. Your Part D premium will depend on your plan and income.

Medicare supplement/Medigap

Medicare supplement insurance — also called Medigap — is optional coverage. This is additional insurance from a private company that can help reduce your out-of-pocket costs. To qualify, you must have Original Medicare (Part A and Part B) and not Part C (Medicare Advantage).

Medigap can help cover deductibles, co-insurance, and copayments. The cost for Medigap varies by insurer, so be sure to compare costs and options.

How to enroll in Medicare

If you want to get a Medicare health plan, here’s how to enroll:

1. Evaluate your eligibility. You may be automatically enrolled in Original Medicare when you receive Social Security benefits and turn 65, after receiving 24 months of disability payments, or if you have ALS. If you’re not in one of those categories, follow the next steps.

2. Gather information. To enroll in Medicare, you’ll need to provide some personal information. This includes your birthplace and your Social Security number, as well as a start and end date for a potential group health plan.

3. Submit an online application. You can apply for Medicare Part A and Part B (Original Medicare) through Social Security, which has an online application. For example, people age 65 and older but not yet receiving Social Security benefits need to apply. About two weeks later, you’ll receive a “Welcome to Medicare” package with your Medicare card and more information about the program.

4. Consider other plans. You have multiple options for Medicare coverage, including Original Medicare (Parts A and B) or Medicare Advantage (Part C). If you have Original Medicare, you may also opt for Part D, prescription drug coverage, and Medigap to cover out-of-pocket costs associated with Original Medicare. But if you have Medicare Advantage, your policy will include prescription drug coverage, and you won’t be allowed to have a Medigap policy.

5. Pay premiums. If you’re getting Social Security benefits, you’ll receive your benefits minus your Medicare premiums. Others will receive a bill.

If you have end-stage renal disease and want to sign up for Medicare, you’ll need to contact a representative at 1 (800) 772-1213 and let them know your situation.

For others who’d like an alternative to applying online, you can also call 1 (800) 772-1213 to talk to a representative. If you’re unsure how to sign up for Medicare, you can use an enrollment tool on the Medicare.gov website.

Late-enrollment penalties

If you fail to enroll for Medicare during your initial enrollment period, you’ll face a monthly late-enrollment penalty tacked on to your premium.

The initial enrollment period spans seven months, including the three months before your 65th birthday, your birthday month, and three months after your birthday month. It’s important to note that it’s not a one-time fee but typically a lifetime penalty.^[4] You may also face additional late-enrollment penalties for specific parts of Medicare.

• 

  Part A

  • When you face the penalty: If you need to pay a premium for Part A because you don’t qualify to get it free and don’t buy it once you’re eligible for Medicare.

  • Late enrollment penalty: The penalty is a 10% monthly premium increase for double the amount of time you weren’t signed up. So, if you didn’t sign up for Part A for one year, you’d pay the penalty for two years. You may avoid the penalty if you meet the eligibility requirements to sign up during the special enrollment period.

• 

  Part B

  • When you face the penalty: If you’re eligible for Medicare Part B and didn’t sign up.

  • Late enrollment penalty: You’ll face a 10% premium increase for every year you weren’t signed up but were eligible to enroll. Rates also depend on income; if you have a higher income, you may pay more. If you’re eligible for the special enrollment period, you can avoid this penalty.

• 

  Part C

  • When you face the penalty: If you don’t sign up for Medicare Part D prescription drug coverage when you’re eligible to do so or if there’s a lapse of 63 days or more in which you don’t have comparable coverage.

  • Late enrollment penalty: You’ll pay a1% increase each month up to 12% per year. Rates may also be higher based on your income.

In most cases, you can avoid these late-enrollment penalties if you sign up for coverage when you qualify or if you’re eligible to enroll during a special enrollment period. Typically, you’ll qualify for this period during certain life events and situations, such as losing Medicaid coverage, or if you had health insurance through your job or your spouse’s job.

When Medicare starts FAQs