Medicare is the cornerstone of health care for more than 70 million Americans¹—including adults 65 and older and younger people with certain disabilities. It’s made up of several parts, each providing a different type of coverage.

Whether you're approaching Medicare eligibility or helping someone else understand their options, this guide break down the basics of original Medicare, what it covers, and the out-of-pocket costs you need to consider.

Original Medicare: Quick Facts

What is original Medicare?

Also called traditional Medicare, original Medicare refers to Medicare Parts A and B. It works on a fee-for-service basis, meaning you can go to any provider or hospital in the U.S. that accepts Medicare. When those covered services are billed, Medicare pays a portion, and you pay the rest. While original Medicare covers healthcare visits and medical supplies, it doesn’t cover all medical expenses or the cost of long-term care.

What is the difference between Medicare Part A and Part B?

Medicare Part A coverage: Hospital Insurance

Medicare Part A is often called hospital or inpatient insurance because it pays for care you receive in the hospital. Part A also pays some of the costs of stays at skilled nursing facilities, or health care at home. Finally, Part A covers hospice care for people who are terminally ill.

Medicare Part A is funded by the payroll tax (FICA) that is deposited into the Hospital Insurance Trust Fund. Most people who have a personal or spousal work history and paid into Social Security do not have to pay a premium for Part A.

Medicare Part B coverage: Medical Insurance

Medicare Part B pays for physician services, outpatient hospital care, and home health care that Part A does not pay for.

It also covers:

• Diagnostic and laboratory tests, such as X-rays and blood work
• Medical equipment, such as wheelchairs and hospital beds
• Orthotics (devices that support joints) and prosthetics (artificial body parts)
• Mental health care
• Ambulance services

Medicare Part B also covers numerous preventive services to help older adults and people with disabilities stay healthy. These include an Annual Wellness Visit, cancer screenings, vaccines, and testing and management of chronic conditions.

Part B is financed by Part B premiums (paid monthly by Medicare beneficiaries) and general revenues from the federal government.

"Medicare Parts A and B create the basic framework of Medicare coverage," explained Ryan Ramsey, NCOA Associate Director of Health Coverage and Benefits. "Together, they make sure older adults have access to both inpatient and everyday medical care."

Which type of care is not covered by Medicare?

Original Medicare (Parts A and B) does not cover most outpatient prescription drugs. If you want coverage for medications prescribed by your health care provider, you'll typically need to enroll in a separate, standalone Medicare Part D prescription drug plan or choose a Medicare Advantage plan that includes prescription drug coverage.

Original Medicare also does not cover:

• Routine dental care
• Routine vision care (such as eye exams for glasses)
• Routine hearing exams and hearing aids
• Most long-term care (custodial care in a nursing home or assisted living)
• Most home health care, other than in very specific circumstances for those requiring specialized therapies

While original Medicare generally doesn’t cover routine dental, vision, and hearing care, it may cover certain medically necessary services related to diagnosing or treating covered medical conditions.

Many people enroll in a Part D plan, Medigap policy, or Medicare Advantage plan to help cover some of these services.

How much is Medicare Part A and B?

All people with original Medicare have costs such as premiums, copayments, and deductibles. (See our chart of Part A and B costs in 2026.) Unlike Medicare Advantage plans, original Medicare does not include an annual limit on out-of-pocket spending for covered services.

For people who have limited incomes, the Medicare Savings Programs can help to pay for the costs of original Medicare. Three of the four available MSPs cover the Medicare Part B premium (which in 2026 is $202.90 a month).

What's the difference between original Medicare and Medicare Advantage?

Original Medicare and Medicare Advantage both provide Medicare coverage, but they work a bit differently. Original Medicare is administered by the federal government and offers relatively stable coverage from year to year. While premiums, deductibles, and other cost-sharing can change annually, the core Part A and Part B benefits generally remain the same. Plus, you can usually see any provider nationwide who accepts Medicare assignment.

Medicare Advantage plans, on the other hand, are issued by private insurance companies and may offer extra benefits like dental care, vision care, and transportation. Most plans also include Medicare Part D prescription drug coverage.

Unlike original Medicare, the vast majority of Medicare Advantage plans use provider networks, which means you’re restricted to certain doctors and hospitals. What’s more, these plans may change their provider networks, premiums, copays, prescription drug formularies, and benefits from year to year. Beneficiaries should review their Annual Notice of Change (ANOC) to make sure their plan still fits their needs and budget.

When do you enroll in original Medicare?

Do you have to sign up for Medicare? Older adults who receive Social Security or Railroad Retirement Benefits will be enrolled automatically into Medicare at age 65. Others not receiving Social Security or Railroad Retirement benefits will have to apply for Medicare through the Social Security Administration during the annual Open Enrollment Period (Oct. 15 – Dec. 7). Younger adults with disabilities generally will be enrolled automatically following 24 months of Social Security disability benefits (SSDI). But people with certain disabilities may be able to get Medicare sooner.

There are several other enrollment opportunities for people to enroll in Medicare. Everyone gets an Initial Enrollment Period for Medicare around their 65th birthday, which last three months prior to the month you turn 65, the month you turn 65, and three months after. There are also Special Enrollment Periods, such as for those who continue to work past age 65 and keep their employer insurance, and an annual General Enrollment Period, taking place Jan. 1 – March 31 of each year.

The date that Medicare benefits begin depends on when a person enrolls, as this enrollment calendar illustrates. Older adults turning 65 may be able to delay enrollment into Medicare under some circumstances, such as having existing coverage through an employer. 

How do you enroll in original Medicare?

Contact the Social Security Administration online or at 1-800-772-1213 (TTY 1-800-325-0778) to enroll in Medicare during your Initial Enrollment Period or another applicable enrollment period. If you’re wondering, “How do I get a replacement Medicare card?”, Social Security can also help you get a new card if you cannot locate yours.

You have choices for how you get Medicare coverage. If you choose original Medicare, you may also be able to purchase a Medicare Supplement Insurance (Medigap) policy from a private insurance company to help cover deductibles, coinsurance, and other out-of-pocket costs not paid by Medicare.

Where is the best place to get advice on Medicare?

Choosing a Medicare plan(s) can feel overwhelming. That's why it's a good idea to get advice from someone who knows the program inside and out. Your local State Health Insurance Assistance Program (SHIP) provides free, unbiased counseling to people with Medicare and their families. To find your SHIP and talk to a trained counselor, call toll-free 1-877-839-2675 or visit the SHIP website.

You can also call Medicare directly at 1-800-633-4227 (TTY users can call 1-877-486-2048). Representatives are available 24 hours a day, 7 days a week (except for some federal holidays).

Frequently asked questions

Who is eligible for original Medicare?
Most people can sign up for original Medicare when they turn 65. You may also qualify before age 65 if you’re living with certain disabilities or medical conditions, such as end-stage renal disease or amyotrophic lateral sclerosis (ALS).

Can I see any doctor with original Medicare?
Yes. One of the biggest benefits of original Medicare is that you can usually see any doctor or hospital in the U.S. that accepts Medicare assignment. You generally don't need a referral to see a specialist.

Does original Medicare cover prescription drugs?
No. Original Medicare doesn't cover most outpatient prescription drugs. If you want help paying for medications prescribed by your doctor, you'll typically need to enroll in a separate Medicare Part D drug plan.

Source

1. Centers for Medicare & Medicaid Services (CMS). Medicare Monthly Enrollment. April 2026. Found on the internet at https://data.cms.gov/summary-statistics-on-beneficiary-enrollment/medicare-and-medicaid-reports/medicare-monthly-enrollment