Medicare is a health insurance option available to individuals 65 and older and those with certain health conditions or disabilities. Medicare covers healthcare, from doctor visits and hospitalization to medications.

Medicare is a government-funded health insurance program available primarily to Americans 65 and older. It should not be confused with Medicaid, another health insurance program available to qualifying Americans with low income.

There are many different options for Medicare coverage, so it’s important to understand what type of coverage each plan can offer you.

In this article, we will explore everything you need to know about Medicare basics, from coverage and costs to enrollment and more.

Medicare is a government-funded program that provides health insurance to Americans who are age 65 and older. Some individuals younger than age 65 and have chronic health conditions or disabilities may also be eligible for Medicare coverage.

Original Medicare (parts A and B) covers most hospital and medical needs. Other parts of Medicare are Part C, Part D, and Medigap. These are private insurance plans that offer additional benefits and services.

You can choose the best plan or combination of plans for your healthcare needs and budget by considering your health conditions, medications, and the doctors you need to see regularly.

Medicare consists of multiple “parts” that you can enroll in for different types of healthcare coverage:

  • Medicare Part A: This is hospital insurance. It covers services you receive when admitted to a hospital or other inpatient healthcare facility. it doesn’t cover outpatient care, as well as most hospital room amenities, private and custodial care, or long-term care.
  • Medicare Part B: This is medical insurance. It covers outpatient diagnostic and treatment services related to your health conditions. It also covers a host of preventive services. Together, Medicare parts A and B are known as “Original Medicare.”
  • Medicare Part C: Also known as Medicare Advantage, this is a private insurance option that covers both Medicare Part A and Part B services. It covers everything under Original Medicare Part A and Part B, along with additional benefits like drug, vision, or dental in many cases. Find the best Medicare Advantage plan for you.
  • Medicare Part D: This prescription drug coverage can be added to Original Medicare. Each Medicare prescription drug plan has a formulary or list of approved drugs that are covered. Each plan has its rules, so it’s important to consider these when comparing plans.
  • Medigap: This is also known as Medicare supplemental insurance and can be added to Original Medicare. It helps cover some of your out-of-pocket Medicare costs. You will pay a separate premium for this plan. There are currently 10 different Medigap plans to choose from.

Most people are eligible to begin enrolling in Original Medicare 3 months before their 65th birthday. However, there are some situations when you may be eligible for Medicare coverage at any age. These exceptions include:

  • Certain disabilities: If you receive monthly disability benefits through the Social Security Administration or Railroad Retirement Board (RRB), you’re eligible for Medicare after 24 months.
  • Amyotrophic lateral sclerosis (ALS): If you have ALS and receive Social Security or RRB benefits, you’re eligible for Medicare from the first month.
  • End-stage renal disease (ESRD): If you have ESRD, you are automatically eligible to enroll in Medicare.

Once enrolled in Medicare parts A and B, eligible Americans can enroll in a Medicare Advantage plan.

Most people eligible for Medicare coverage must enroll during the enrollment period. The periods and deadlines for Medicare enrollment include:

  • Initial enrollment: This includes the 3 months before, the month of, and the 3 months after you turn age 65.
  • General enrollment: This is from January 1 through March 31 if you missed your initial enrollment period. However, late enrollment fees may apply.
  • Special enrollment: This option is available for a certain number of months, depending on your reason for qualifying.
  • Medigap enrollment: This includes the 6 months after you turn 65 years old.
  • Medicare Part D enrollment: If you missed your initial enrollment period, you can sign up during the open enrollment period between October 15 and December 7. At this time, you can enroll in, drop, or change any Medicare plan.

You will be automatically enrolled into Medicare parts A and B if:

  • you’re turning age 65 within 4 months and have been receiving disability benefits
  • you’re not turning age 65 but have been receiving disability benefits for 24 months
  • you’re not turning age 65 but have been diagnosed with ALS or ESRD

Individuals not automatically enrolled in Medicare must enroll through the Social Security website. If you do not sign up during the enrollment period, there are penalties for late enrollment.

Your Medicare costs will depend on what type of plan you have.

Part A costs

In 2025, Medicare Part A costs include:

  • Part A premium: as low as $0 (premium-free Part A) or as high as $518 per month, depending on how long you or your spouse has worked over your lifetime
  • Part A deductible: $1,676 per benefit period
  • Part A coinsurance: ranging from $0 to the full cost of services depending on the length of your stay

Part B costs

In 2025, Medicare Part B costs include:

Part C costs

You still need to pay the Original Medicare costs when you enroll in Medicare Part C. Medicare Advantage plans may also charge plan costs, which can include:

  • monthly premium
  • yearly deductible
  • prescription drug deductible
  • copayments and coinsurance

According to the Centers for Medicaid & Medicare (CMS), the average monthly premium for Part C plans is around $17.00 in 2025.

Part D costs

You will pay a separate premium for a Medicare Part D plan and copayments for your prescription drugs. These copayment amounts vary based on which formulary “tier” your prescription drugs fall into. Each plan has different costs and drugs included in its tiers. The national base beneficiary premium is $36.78 in 2025.

Medigap costs

You will pay a separate premium for a Medigap policy. However, remember that Medigap plans are intended to help offset some of the other Original Medicare costs.

Some of the ways to pay your Medicare bill each month include:

  • Medicare’s website, with a debit or credit card
  • by mail, using a check, money order, or payment form

Another way to pay your Medicare bill is through Medicare Easy Pay. This free service allows you to pay your monthly Medicare Part A and Part B premiums through automatic bank withdrawals.

Medicare billing

Most people don’t receive a bill from Medicare. Part B premiums are automatically deducted from your Social Security or Railroad Retirement Board benefit payments.

If you don’t receive Social Security or Railroad Retirement Board benefit payments, then you will receive a bill from Medicare.

Medicare is a popular health insurance option for Americans who are age 65 and older or have certain disabilities. Medicare Part A covers hospital services, while Medicare Part B covers medical services.

Medicare Part D helps cover prescription drug costs, and a Medigap plan helps cover Medicare premium and coinsurance costs. Medicare Advantage plans offer the convenience of all the coverage options in one place.

To find and enroll in a Medicare plan in your area, visit Medicare.gov and use the online plan finder tool. Note that you may be eligible for both Medicare and Medicaid coverage. If this happens, Medicare will be your primary insurance coverage, and Medicaid will be your secondary insurance coverage to help with costs and other services not covered by Medicare.

Medicare plan options and costs are subject to change each year.