What Is Medicare Part A and Part B Coverage Explained

If you are approaching 65, leaving an employer plan, or helping a parent navigate retirement, the two words you will hear most often are Part A and Part B. Together they form Original Medicare, the federal health insurance program that covers hospital care, doctor visits, and a long list of related services. Understanding what each part pays for, what it does not, and how the pieces fit together can save you thousands of dollars in surprise medical bills. This guide breaks down Medicare Part A and Part B coverage in plain language so you can make confident decisions about your health care.

The Foundation: What Original Medicare Actually Is

Original Medicare is the government-run health insurance program administered by the Centers for Medicare and Medicaid Services (CMS). It has two main components: Part A, which covers inpatient hospital stays and certain facility-based care, and Part B, which covers outpatient medical services, preventive care, and durable medical equipment. When people ask "What is Medicare Part A and Part B coverage explained," they are really asking how these two halves work together to form a complete, though not comprehensive, health plan.

One of the most important things to understand is that Original Medicare is not a replacement for the kind of coverage you may have had through an employer. It pays a share of your medical costs, but it leaves gaps. Those gaps, including deductibles, coinsurance, and services Medicare does not cover at all, are where Medicare Supplement plans and Medicare Advantage plans come into play. Before you shop for extra coverage, however, you need a firm grasp of what the foundation provides.

Original Medicare also operates on a fee-for-service model. That means you can generally see any doctor or hospital in the country that accepts Medicare assignment. There are no networks to check in most cases, and you do not need a referral to see a specialist. This flexibility is a major selling point for many beneficiaries, but it also means you are responsible for a larger share of the bill compared to managed care plans.

Medicare Part A Coverage: Hospital and Inpatient Care

Medicare Part A is often called hospital insurance, and that nickname is accurate. It covers inpatient care you receive after being formally admitted to a hospital, as well as care in skilled nursing facilities, hospice care, and some home health care. The key word here is "inpatient." If you are placed under observation rather than admitted, Part A may not pay, and you could face a different set of costs under Part B. This distinction trips up many beneficiaries, so it is worth confirming your status with the hospital.

Part A coverage generally includes the following services:

• Inpatient hospital stays, including semi-private rooms, meals, nursing care, and medications administered during your stay
• Skilled nursing facility care after a qualifying hospital stay, when skilled nursing or rehabilitation is medically necessary
• Hospice care for terminally ill patients, including pain relief, counseling, and respite care for caregivers
• Some home health care services, such as part-time skilled nursing care and physical therapy, when you meet specific conditions
• Inpatient care in a religious nonmedical health care institution

What Part A does not cover is just as important. It does not pay for long-term custodial care, which is help with daily activities like bathing, dressing, and eating when that is the only care you need. It also does not cover private-duty nursing, a private room unless medically necessary, or the first three pints of blood you receive in a hospital stay. Those blood units are covered by Part B or a supplement, depending on the situation.

If you ever need surgery during a hospital stay, Part A generally covers the facility costs, including the operating room and recovery room. However, the surgeon's professional fees are typically billed under Part B. Understanding this split helps you anticipate which part of Medicare is responsible for which portion of your bill. For a deeper look at how surgical fees are handled, our guide on understanding Medicare Part A coverage for surgeon fees walks through the details.

Medicare Part B Coverage: Doctors, Tests, and Preventive Care

Medicare Part B is medical insurance, and it is the part you will interact with most often. It covers doctor visits, outpatient hospital care, lab tests, imaging, mental health services, and preventive screenings. If you have ever gone to a clinic for a checkup, a blood draw, or a flu shot, that is Part B at work. Unlike Part A, which is usually premium-free for people with enough work history, Part B requires a monthly premium that most beneficiaries pay directly.

Part B coverage includes a wide range of medically necessary services and supplies. Common examples include:

• Doctor visits, both primary care and specialist visits, whether in an office or outpatient setting
• Preventive services such as annual wellness visits, mammograms, colonoscopies, and vaccines for flu, pneumonia, and COVID-19
• Diagnostic tests and imaging, including X-rays, MRIs, CT scans, and blood work
• Durable medical equipment like wheelchairs, walkers, hospital beds, and oxygen equipment for home use
• Outpatient mental health care, including therapy and counseling
• Ambulance services when medically necessary

Part B also covers some drugs that are not typically self-administered, such as chemotherapy infusions, injectable medications given in a doctor's office, and certain oral cancer drugs. For most prescription medications you take at home, you will need a separate Part D plan. That is a common point of confusion, so remember: Part B handles drugs administered by a health care provider, while Part D handles self-administered prescriptions.

One of the most valuable aspects of Part B is its preventive focus. Many screenings and vaccines are covered at no cost to you when you see a provider who accepts Medicare assignment. That means you can get your annual wellness visit, your mammogram, and your diabetes screening without paying a copay or coinsurance, as long as the service is recommended and the provider is in the program. Taking advantage of these benefits is one of the easiest ways to stay healthy and avoid larger medical costs down the road.

How Part A and Part B Work Together: Costs and Coordination

Understanding the costs associated with Part A and Part B is essential because Original Medicare does not cap your out-of-pocket spending. Unlike many private plans, there is no annual maximum on what you might pay. That is why many beneficiaries pair Original Medicare with a Medicare Supplement plan, also called Medigap, to cover the gaps.

Here is how the cost structure breaks down for 2026. Part A has a deductible for each benefit period, which is a period of time that starts when you are admitted as an inpatient and ends when you have been out of the hospital for 60 consecutive days. For 2026, the Part A deductible is $1,736 per benefit period. There is no coinsurance for the first 60 days of a hospital stay, but days 61 through 90 require a daily coinsurance amount, and days beyond 90 use lifetime reserve days with a higher daily cost. Skilled nursing facility care has its own coinsurance structure after the first 20 days.

Part B has a monthly premium and an annual deductible. The standard Part B premium for 2026 is $202.90 per month for most beneficiaries, though higher-income individuals pay more through an income-related monthly adjustment amount (IRMAA). The Part B deductible is $283 per year. After you meet the deductible, you typically pay 20 percent of the Medicare-approved amount for most services. There is no cap on that 20 percent, which is why a serious illness can lead to significant out-of-pocket costs.

Understanding how the two parts coordinate is crucial. If you have a hospital stay that includes surgery, Part A covers the facility costs while Part B covers the surgeon's fees and any outpatient follow-up. If you are admitted for observation rather than as an inpatient, Part B may cover the entire stay, which can mean different cost-sharing. Keeping track of which part is responsible for which service helps you spot billing errors and avoid paying more than you owe.

What Original Medicare Does Not Cover

Even with a solid understanding of Part A and Part B, you should know that Original Medicare leaves several significant gaps. These gaps are the reason many beneficiaries choose to add supplemental coverage. The most common exclusions include:

• Long-term care, also called custodial care, which is help with daily activities when you do not need skilled medical care
• Routine dental care, including cleanings, fillings, and dentures
• Routine vision care, including eyeglasses and contact lenses
• Hearing aids and routine hearing exams
• Cosmetic surgery, unless it is medically necessary
• Prescription drugs you take at home, which require a Part D plan
• Care received outside the United States, with very limited exceptions

These exclusions are not oversights; they reflect the original design of the program, which focused on acute medical care rather than long-term or routine services. If you want coverage for dental, vision, hearing, or prescription drugs, you will need to explore Medicare Advantage plans, which often bundle these benefits, or purchase standalone policies. Understanding what is not covered is just as important as understanding what is, because it allows you to plan and budget accordingly.

For agents and agencies who work with Medicare beneficiaries, knowing these gaps is a powerful sales tool. When you can explain exactly what Original Medicare does not pay for, you demonstrate expertise and build trust. That trust is the foundation of a long-term client relationship, and it is what separates successful agents from those who struggle to close deals.

Enrollment, Eligibility, and Avoiding Penalties

Most people become eligible for Medicare when they turn 65, though some qualify earlier due to disability or certain medical conditions. If you are already receiving Social Security benefits, you will be automatically enrolled in Part A and Part B, and your card will arrive in the mail a few months before your 65th birthday. If you are not receiving Social Security, you will need to sign up through the Social Security Administration website or by visiting a local office.

The Initial Enrollment Period is a seven-month window that begins three months before your 65th birthday month, includes your birthday month, and ends three months after. Enrolling on time is critical because late enrollment can trigger permanent penalties. The Part B late enrollment penalty adds 10 percent to your monthly premium for each 12-month period you were eligible but did not enroll, and that penalty lasts as long as you have Part B. Part A has a similar penalty for those who must pay a premium.

There are exceptions. If you have employer coverage through active employment, you may be able to delay Part B without penalty. This is a common situation for people who continue working past 65. You will need to coordinate with your employer's HR department and follow the rules for Special Enrollment Periods. If you miss your window and do not qualify for an exception, you may have to wait until the General Enrollment Period, which runs from January 1 to March 31 each year, with coverage starting the following month.

For agents, helping clients navigate enrollment is a value-added service that sets you apart. A client who avoids a penalty because of your guidance is a client who will refer friends and family. If you are looking to grow your book of business with high-quality prospects who are actively researching their options, platforms like PingPost.Exchange offer real-time lead distribution and auction technology that can connect you with motivated buyers. This kind of tool is especially useful for agents who want to scale their outreach without sacrificing lead quality.

How Part A and Part B Fit with Medicare Advantage and Medigap

Original Medicare, which includes Part A and Part B, is one way to receive your Medicare benefits. Another way is Medicare Advantage, also known as Part C. Medicare Advantage plans are offered by private insurance companies approved by Medicare, and they provide at least the same coverage as Part A and Part B. Many include extra benefits like dental, vision, hearing, and prescription drug coverage. When you enroll in a Medicare Advantage plan, you still have Part A and Part B, but the plan administers your benefits and you generally must use the plan's network of providers.

Medigap plans, on the other hand, work alongside Original Medicare. They do not replace it; they supplement it. A Medigap policy helps pay for costs that Original Medicare does not cover, such as deductibles, coinsurance, and copayments. Medigap plans are standardized by letter in most states, so a Plan G in one state offers the same basic benefits as a Plan G in another. The main difference is the premium, which varies by insurer and location.

Choosing between Medicare Advantage and Medigap is one of the most important decisions a beneficiary will make. Medicare Advantage plans often have lower premiums but higher out-of-pocket costs when you need care, and they may restrict you to a network. Medigap plans have higher premiums but offer more predictable costs and greater provider flexibility. There is no one-size-fits-all answer; the right choice depends on your health, your budget, and your tolerance for risk.

Key Takeaways for Beneficiaries and Agents

Whether you are a beneficiary trying to understand your coverage or an agent helping clients make informed choices, the fundamentals of Medicare Part A and Part B are the same. Part A covers inpatient hospital care, skilled nursing facility care, hospice, and some home health care. Part B covers doctor visits, outpatient care, preventive services, and durable medical equipment. Together they form Original Medicare, which is the foundation of most Medicare coverage strategies.

The gaps in Original Medicare are significant, and they are where supplemental coverage becomes essential. Deductibles, coinsurance, and excluded services can add up quickly, especially for beneficiaries with chronic conditions or those who require extensive medical care. Understanding these gaps allows you to plan ahead and avoid financial surprises.

For agents, mastering the details of Part A and Part B is not just about compliance; it is about credibility. When you can explain the difference between inpatient and observation status, or clarify why a patient might owe 20 percent of a large bill, you become a trusted advisor rather than just a salesperson. That trust is what drives referrals, renewals, and long-term success in the Medicare market. Whether you are new to the industry or a seasoned professional, continuing to educate yourself on Medicare basics is one of the best investments you can make in your business.