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What Is Original Medicare?

This combo of Part A and Part B was the starting point for older Americans’ health care, decades before Medicare Advantage

5-minute read

Article 5 of 11 in Medicare Parts

Kimberly Lankford and Jacqueline Salmon,

Updated October 06, 2026

AARP

Reviewed by

Claire Noël-Miller, MPA, Ph.D.

En español

Updated October 06, 2026

a doctor examining a patient inside a large tent styled like a Medicare card next

Rob Dobi

Key takeaways

Parts A and B are the foundation of older adults’ health care.
Original Medicare is all about providing options.
Other insurance is available to fill gaps in coverage.
Original Medicare differs from Medicare Advantage.

Original Medicare, sometimes called traditional Medicare, combines Part A insurance for hospitalization and Part B coverage for everyday medical services into the federal government’s foundation of health care for older Americans.

When President Lyndon B. Johnson signed Medicare into law in 1965, Part A and Part B were inaugural pieces of a health care program that later expanded to include private Medicare Advantage and prescription drug plans as well as coverage for younger people with disabilities. Though Medicare enrollees have more choices than 60 years ago, those parts remain at the core:

Part A helps pay for inpatient stays in hospitals and skilled nursing facilities, some home care and end-of-life hospice care.
Part B covers doctors’ services, diagnostic screenings, lab tests, outpatient care, preventive services, plus some medical equipment and transportation.

Original Medicare offers options in providers, hospitals

These days, 99 percent of adults 65 and older are eligible for Medicare either through their work history or their spouse’s employment, according to the U.S. Census Bureau. Be aware that federal law will change that eligibility in 2027 for some legal immigrants who have paid Medicare taxes for decades.

No provider networks. With original Medicare, you can use any health care professional, clinic or medical center in the United States that accepts Medicare. About 98 percent of physicians who aren’t pediatricians participate, and you don’t need permission to see a specialist.

Original Medicare has no insurance company standing between you and your doctor. The federal government, primarily using payroll taxes, general fund revenue and enrollees’ monthly premiums, pays providers directly.

Care isn’t free. Almost all who turn 65 qualify for premium-free Part A.

But everyone who doesn’t get financial assistance has to pay at least $202.90 a month in 2026 for Part B. High earners pay monthly premium surcharges that rise with their income.

And when you use Part A and Part B services, you’ll generally be responsible for deductibles, copayments and coinsurance.

But the law that established insurance for these services was mum on a limit for enrollees’ out-of-pocket costs, an oversight that some lawmakers are trying to remedy with a Senate bill to cap those costs at $5,000 in 2028. AARP supports this legislation because it gives people on original Medicare similar protections as those who have Medicare Advantage and prescription plans.

Add-ons fill in what original Medicare doesn’t cover

Original Medicare wasn’t designed to cover all your health care needs. The law specifically excluded most dental, hearing, vision, long-term care and prescriptions.

Bills through the years have sought to add those benefits to original Medicare. The big success was the creation of the Part D drug plan through a law passed in 2003 that became effective in 2006.

Why you need Part D. As you age, you may find that you must manage more than one chronic condition at a time, such as high blood pressure, high cholesterol and arthritis. Having insurance to help pay for your medicines can come in handy.

But the law is designed to discourage buying coverage only when you need it most.

You’ll face a lifetime penalty if you go 63 days in a row or longer without drug coverage that’s at least as good as the Part D policies you can buy through Medicare’s Plan Finder, what’s called creditable coverage. Prescription plans from a present employer, a former employer, Tricare for Life for military retirees or Veterans Affairs health care can be considered creditable coverage.

Why you’ll want a Medigap plan. The nickname for Medicare supplemental insurance says it all. These policies pay for some of the gaps in original Medicare that otherwise would be your responsibility.

While you can buy a Medigap plan at any time after you turn 65, in most states you could pay more or be rejected if you wait longer than six months after getting Medicare Part B. After that Medigap open enrollment period when you can buy the plan of your choice at the least expensive rates, insurers can use your health problems to raise your premium, delay or deny coverage.

While Medigap plans won’t pay for the dental, hearing and vision services that original Medicare doesn’t cover, a few do offer policies to purchase, limited benefits or discounts.

How original Medicare differs from Medicare Advantage

Medicare Advantage includes the two pillars of original Medicare: Part A and Part B. You’ll pay a Part B, and perhaps a Part A, premium no matter which option you choose.

Original Medicare through the federal government is all about choice. You get to decide on:

The hospitals and health care providers you like
The Part D prescription plan that meets your needs each year
A Medigap plan or similar insurance you already have that will work with you as you age and use more services

Medicare Advantage, sold by private companies that contract with the federal government, gives you a package:

Parts A, B and often D rolled into one plan
Lists of in-network providers, pharmacies and medications
Some coverage for dental, hearing and vision care

Because most Medicare Advantage plans have a provider network, doctors you have already who are not part of the network could cost you more or not be covered at all. You may need permission from the plan’s officials, called prior authorization, to see a specialist.

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This story, originally published Aug. 28, 2014, has been updated to focus on the features of original Medicare, who’s eligible, what it doesn’t cover, plans that complement it and how it differs from Medicare Advantage.

About the authors

Kimberly Lankford is a contributing writer who covers Medicare and personal finance and now writes about insurance for The Wall Street Journal | Buy Side. She wrote about insurance, Medicare, retirement and taxes for more than 20 years at Kiplinger Personal Finance and has written for The Washington Post and The Boston Globe. She received the personal finance Best in Business award from the Society of American Business Editors and Writers and the New York State Society of Certified Public Accountants’ excellence in financial journalism award for her guide to Medicare.

Jacqueline Salmon is a book and magazine writer-editor specializing in health and wellness topics and memoir. She is a former Washington Post reporter and editor who covered health, finance, business and other topics.

About the reviewer

Claire Noël-Miller, senior strategic policy adviser for Medicare at the AARP Public Policy Institute, previously worked as a postdoctoral researcher and a research associate at the Center for the Demography of Health and Aging at the University of Wisconsin-Madison. She earned her master’s degree in public affairs from Princeton University and her doctorate in demography from the University of Pennsylvania.