Original Medicare is the federal health insurance program run directly by Medicare, not a private insurance company

Original Medicare has two parts: Part A covers hospital stays, skilled nursing facility care, hospice, and some home health services. Part B covers doctor visits, outpatient care, medical equipment, and preventive services. When you turn 65, you are automatically enrolled in Parts A and B if you are a U.S. citizen or permanent resident who has lived in the country for at least five years.

The program is funded through payroll taxes (the Medicare tax you see on your paychecks) and monthly premiums you pay directly to Medicare. You pay a deductible before Medicare starts paying, and you share the cost of most services through copayments and coinsurance. Original Medicare does not cover dental, vision, hearing aids, or long-term care — those gaps are why many people add supplemental coverage.

Key Takeaways

  • Part A covers hospital and skilled nursing care; Part B covers doctor visits and outpatient services, and both are run directly by the federal government.
  • You pay a yearly deductible for Part A hospital care and a different yearly deductible for Part B, then share costs through copayments and coinsurance.
  • Original Medicare does not cover dental, vision, hearing aids, or prescription drugs unless you add Part D coverage for medications.
  • You can see any doctor or hospital that accepts Medicare, with no network restrictions like you would have with a private Medicare plan.
  • If Original Medicare does not cover enough of your costs, you can buy a Medigap supplemental policy or switch to a Medicare Advantage plan.

How Part A and Part B work together

Part A is hospital insurance. It covers the full cost of the first three days of a hospital stay (after you pay the deductible), then you pay coinsurance for days 4 through 60, and a higher coinsurance amount for days 61 through 90. If you need a skilled nursing facility after a hospital stay — for example, physical therapy after surgery — Part A covers up to 100 days, with you paying nothing for the first 20 days and coinsurance for days 21 through 100. Part A also covers hospice care if you have a terminal illness, and some home health services if you are homebound and a doctor orders them.

Part B is medical insurance. It covers doctor office visits, emergency room care, lab tests, imaging, outpatient surgery, and durable medical equipment like wheelchairs or oxygen. Part B also covers preventive services at no cost to you — things like annual wellness visits, cancer screenings, and vaccinations. You pay 20 percent coinsurance for most Part B services after you meet your yearly deductible, which means Medicare pays 80 percent.

Both parts require you to use providers who accept Medicare. Most doctors and hospitals do, but you should always ask before scheduling an appointment or procedure. If a provider does not accept Medicare, you may have to pay the full bill yourself.

What you pay out of pocket

Original Medicare requires you to pay several types of costs. You pay a monthly premium for Part B (the amount varies by income, but most people pay the standard amount set each year). You also pay an annual deductible for Part A hospital care and a separate annual deductible for Part B. Once you meet the Part B deductible, you typically pay 20 percent of the cost for doctor visits, tests, and equipment.

Hospital stays have a different cost structure. After you pay the Part A deductible, Medicare covers all costs for days 1 through 3. For days 4 through 60, you pay a daily coinsurance amount (not a percentage, but a fixed dollar amount set each year). For days 61 through 90, you pay a higher daily amount. If you stay longer than 90 days, you can use "lifetime reserve days" — 60 additional days that Medicare will help pay for, but at an even higher coinsurance rate. Once you use all your reserve days, you pay everything yourself.

These costs reset each calendar year for Part B. For Part A, the deductible and coinsurance amounts reset each time you have a break of 60 days or more without being an inpatient in a hospital or skilled nursing facility.

Prescription drug coverage and gaps in Original Medicare

Original Medicare does not include prescription drug coverage. If you want Medicare to help pay for medications, you must add Part D, a separate prescription drug plan run by private insurance companies approved by Medicare. Part D is optional, but if you do not sign up when you first become may be able to access and you go without it for more than 63 days, you may have to pay a penalty for the rest of your life.

Original Medicare also does not cover dental care, vision care, hearing aids, or routine foot care. Many people buy a Medigap policy (also called supplemental insurance) to cover some of these gaps and to reduce their out-of-pocket costs for hospital and doctor visits. Medigap policies are sold by private insurance companies but are standardized by federal law, so the same plan letter (like Plan G or Plan N) covers the same benefits no matter which company sells it.

If you want dental, vision, and hearing coverage bundled with your medical insurance, you may want to switch to a Medicare Advantage plan instead. Medicare Advantage is an alternative to Original Medicare run by private insurance companies. It usually includes prescription drug coverage and often includes dental and vision, but it typically has a network of doctors and hospitals you must use.

How to use Original Medicare when you need care

When you see a doctor or go to a hospital, show your Medicare card. The provider will bill Medicare directly. Medicare will pay its share, and you will receive a bill for your share (deductible, coinsurance, or copayment). You do not have to get approval from Medicare before most appointments or procedures — you can see any doctor or specialist without a referral, and you do not have to choose a primary care doctor.

The exception is certain services that require advance approval. For example, if you need durable medical equipment, the supplier may need to get approval from Medicare before providing it. If you are unsure whether something needs approval, ask your doctor or the provider's billing office.

You will receive an Explanation of Benefits (EOB) from Medicare after each service. The EOB shows what the provider charged, what Medicare paid, and what you owe. Keep these documents — they are your record of what you have paid toward your deductible and can help you track your out-of-pocket costs.

Original Medicare versus Medicare Advantage

Original Medicare is fee-for-service insurance: Medicare pays providers for each service you receive, and you can see any doctor or hospital that accepts Medicare. There are no networks, no referrals required, and no prior approval for most care. This flexibility is Original Medicare's main advantage, especially if you travel or see specialists frequently.

Medicare Advantage is an alternative run by private insurance companies. It typically has lower monthly premiums and includes prescription drug coverage and sometimes dental and vision. However, it uses networks like employer health insurance — you usually must see doctors within the plan's network, and you may need a referral to see a specialist. Medicare Advantage plans also have annual out-of-pocket spending limits, which Original Medicare does not.

You can switch between Original Medicare and Medicare Advantage during the annual enrollment period (October 15 to December 7 each year), or if you have a may have access to life event like moving out of your plan's service area. If you choose Original Medicare, you can add Part D for prescriptions and Medigap for supplemental coverage at any time, though waiting may cost you more in penalties.

When Original Medicare starts and how to stay enrolled

You become may be able to access for Original Medicare at age 65. If you are already receiving Social Security benefits, you are automatically enrolled in Parts A and B about three months before your 65th birthday. If you are not yet receiving Social Security, you must contact Social Security to sign up for Medicare. You can do this online at ssa.gov, by phone at 1-800-772-1213, or in person at your local Social Security office.

If you are still working and have health insurance through your employer, you can delay Part B without penalty as long as your employer has 20 or more employees. Once you leave that job or lose the coverage, you have eight months to sign up for Part B without paying a late enrollment penalty. If you miss this window, you will pay a permanent 10 percent increase in your Part B premium for each year you could have been enrolled.

To stay enrolled in Original Medicare, you do not have to do anything — your coverage continues automatically as long as you pay your Part B premium. You do not have to re-enroll each year like you do with Medicare Advantage plans.

Frequently Asked Questions

Do I have to use Original Medicare, or can I choose a different type of Medicare?

You have a choice. When you turn 65, you are automatically enrolled in Original Medicare Parts A and B, but you can switch to a Medicare Advantage plan during the annual enrollment period (October 15 to December 7). You can also switch back to Original Medicare the following year. If you decline Original Medicare when you first become may be able to access and do not have other may have access to coverage, you may pay a penalty.

Can I see any doctor with Original Medicare?

Yes, as long as the doctor accepts Medicare. You do not need a referral, and you do not have to choose a primary care doctor. However, always confirm that a provider accepts Medicare before scheduling an appointment, because some doctors do not participate in the program and may charge you the full bill.

What happens if I need care that costs more than Original Medicare covers?

You pay the difference yourself unless you have supplemental coverage. Many people buy a Medigap policy to cover some of these costs, or they switch to a Medicare Advantage plan, which has an annual out-of-pocket spending limit. Without supplemental coverage, a long hospital stay or expensive procedure can result in significant bills.

Is Original Medicare the same everywhere in the United States?

Yes, the benefits and cost-sharing rules are the same nationwide. However, the amount you pay for Part B premiums can vary based on your income, and the cost of living may affect how far your out-of-pocket money goes. Part D prescription drug plans vary by region and by plan, so you should review your options each year.

What should I do if I disagree with a bill from Original Medicare?

You can request a review of a Medicare decision. If you receive an Explanation of Benefits and believe Medicare made an error, you can file an appeal. The process has multiple levels, starting with a redetermination request. Contact Medicare at 1-800-MEDICARE (1-800-633-4227) or visit Medicare.gov for instructions on how to appeal.