Medicare Part A and Part B Explained: Coverage, Costs and Gaps

What Is Original Medicare?

Original Medicare is the traditional, federally administered health insurance program for people age 65 and older, and for younger people who qualify through disability or certain conditions like end-stage renal disease. It has two parts that work together:

• Part A (Hospital Insurance) pays for care you receive as an admitted patient in a facility.
• Part B (Medical Insurance) pays for the doctors, tests, and outpatient services you use in everyday life.

You can use Original Medicare with any doctor or hospital in the United States that accepts Medicare, which is the vast majority of them. There are no networks and no referrals. In exchange for that flexibility, you pay deductibles and coinsurance on almost every service, and there is no annual cap on your out-of-pocket costs.

What Part A Covers (Hospital Insurance)

Part A is often called "hospital insurance," and it primarily pays for care delivered inside a facility. In 2026, Part A covers:

• Inpatient hospital stays, including your semi-private room, meals, general nursing, drugs given during your admission, and other hospital services and supplies
• Skilled nursing facility (SNF) care after a qualifying inpatient hospital stay of at least three days
• Hospice care for people with a terminal illness, including nursing care, symptom-management drugs, and equipment related to the terminal condition
• Some home health care, typically when it follows a covered inpatient stay
• Inpatient rehabilitation in a rehab facility

When Is Part A Premium-Free?

Most people pay $0 for Part A because they or a spouse paid Medicare taxes long enough while working, generally at least 10 years (40 quarters). You also qualify for premium-free Part A if you are already receiving Social Security or Railroad Retirement Board benefits, or if you have received Social Security disability benefits for at least 24 months.

If you do not qualify for premium-free Part A, you can buy it. In 2026, that premium is $311 per month if you have 30 to 39 quarters of Medicare-covered work, or $565 per month if you have fewer than 30 quarters. To buy Part A, you must also enroll in Part B. If this applies to you, our step-by-step enrollment guide walks through the process.

2026 Part A Costs

The Medicare Part A inpatient hospital deductible in 2026 is $1,736 per benefit period (up $60 from $1,676 in 2025). Hospital coinsurance is $434 per day for days 61-90 of a hospitalization, $868 per day for lifetime reserve days, and $217 per day for skilled nursing facility days 21-100.

What Part B Covers (Medical Insurance)

Part B covers the medical services you use outside a hospital admission. In 2026, Part B pays for:

• Doctor visits in the office, clinic, or as an outpatient
• Outpatient hospital services, including same-day surgery and ER visits
• Preventive services like annual wellness visits, flu shots, and many cancer screenings (often at 100% with no coinsurance)
• Durable medical equipment (DME) such as wheelchairs, walkers, oxygen equipment, hospital beds, and diabetes supplies
• Lab tests, X-rays, and imaging
• Ambulance services
• Outpatient mental health care
• Certain home health services that Part A does not cover
• Physician services during a hospital stay (the facility bill is Part A; the doctor bill is Part B)

2026 Part B Costs

The standard Part B monthly premium in 2026 is $202.90, up $17.90 from $185.00 in 2025. The annual Part B deductible is $283, up $26 from $257 in 2025. After you meet the deductible, you typically pay 20% coinsurance of the Medicare-approved amount for most services.

Higher-income beneficiaries pay an Income-Related Monthly Adjustment Amount (IRMAA) on top of the standard premium. Based on your 2024 tax return, the 2026 Part B premium ranges from $202.90 to $689.90 per month depending on income.

Part A vs. Part B: Side-by-Side

The easiest way to remember the difference is this: if you are formally admitted to a facility, it is Part A. If you are walking in and out under your own power, it is Part B.

Do You Need Both Part A and Part B?

For almost everyone, yes. Part A alone leaves you with no coverage for the doctors you see every year, and Part B alone leaves you exposed to enormous hospital bills. The two parts are designed to work together, and Medigap policies are built assuming you have both.

The only common exception is people who delay Part B because they have creditable employer coverage through active employment. If that is your situation, you can enroll in Part A when you turn 65 and delay Part B without penalty until the employer coverage ends, then use your Special Enrollment Period.

The Coverage Gaps Medigap Is Designed to Fill

Original Medicare is strong, but it has predictable holes. This is where a Medigap (Medicare Supplement) policy comes in. Medigap plans are standardized by the federal government and sold by private insurers, and they pay some or all of the cost-sharing Original Medicare leaves you to pay.

The main gaps a Medigap plan addresses:

1. No annual out-of-pocket limit. Original Medicare will keep charging you 20% forever, whether your bill is $500 or $500,000. Most Medigap plans cover that 20% in full.
2. The Part A hospital deductible. At $1,736 per benefit period, this is one of the biggest single expenses beneficiaries face. Most Medigap plans pay it for you.
3. Coinsurance for extended hospital and SNF stays. All Medigap plans add up to 365 extra hospital days of coverage beyond what Medicare pays.
4. Foreign travel emergency care, which Original Medicare generally does not cover, is included on Plans C, D, F, G, M, and N up to plan limits.

For a full walkthrough of every gap, see our guide on what Medicare doesn't cover. To compare which plan letter fits your budget, our Medigap plans comparison chart breaks down all 10 standardized plans side by side. Most new enrollees today pick Medicare Supplement Plan G, which covers everything except the $283 Part B deductible, or Plan N if they want a lower monthly premium.

Why Most People Also Add a Part D Plan

Neither Part A nor Part B covers most outpatient prescription drugs. To get drug coverage with Original Medicare, you enroll in a standalone Medicare Part D plan sold by private insurers.

In 2026, Part D has a $2,100 annual out-of-pocket cap on covered prescriptions (up from $2,000 in 2025), and the national base beneficiary premium is $38.99. Once you hit the cap, your covered drugs cost $0 for the rest of the year. See our detailed guide on pairing Medigap with Part D to understand how to choose a plan and avoid the late enrollment penalty.

The typical "Original Medicare stack" for a 65-year-old in 2026 looks like this:

• Part A ($0 for most people)
• Part B ($202.90 per month standard)
• Medigap Plan G (roughly $165 to $220 per month at age 65, varies widely by state and carrier)
• Part D drug plan (average standalone PDP premium around $34.50)

Total monthly cost is usually in the $400 to $460 range, and it comes with near-zero surprise bills for the rest of your life. For a full breakdown of what supplement plans cost by age and state, see how much a Medicare Supplement plan costs in 2026.

Frequently Asked Questions

Do I need both Medicare Part A and Part B?

For most retirees, yes. Part A covers hospital stays and Part B covers doctors and outpatient care, so you need both for full protection. The only common reason to delay Part B is if you have active employer group coverage through your own or your spouse's current job. Medigap and Part D also require you to be enrolled in both Parts A and B.

How much does Medicare Part A cost in 2026?

Part A is premium-free for roughly 99% of beneficiaries because they or their spouse paid Medicare taxes for at least 10 years while working. If you do not qualify, you pay $311 per month with 30 to 39 quarters of covered work, or $565 per month with fewer than 30 quarters in 2026. Everyone pays the $1,736 hospital deductible per benefit period plus daily coinsurance if a stay runs longer than 60 days.

What is the Medicare Part B premium and deductible for 2026?

The standard Part B premium is $202.90 per month in 2026, up from $185.00 in 2025. The annual Part B deductible is $283, and after you meet it, Medicare pays 80% of most services while you pay the remaining 20%. Higher-income beneficiaries pay more due to IRMAA surcharges, ranging up to $689.90 per month for individuals with 2024 MAGI of $500,000 or more.

What does Medicare Part A and Part B not cover?

Original Medicare does not cover most outpatient prescription drugs, routine dental care, routine vision (eyeglasses and exams for glasses), routine hearing aids, long-term custodial nursing home care, or health care outside the United States except in rare emergencies. It also has no annual out-of-pocket cap, which is why most people add a Medigap policy plus a Part D drug plan. See our guide comparing Medigap vs. Medicare Advantage to understand the two main ways beneficiaries close these gaps.

How is Part A different from Part B?

Part A covers care you get as an admitted patient in a facility, such as hospital stays, skilled nursing facility care, hospice, and some home health. Part B covers care you receive as an outpatient, including doctor visits, preventive services, lab tests, and durable medical equipment. If you are admitted to a hospital, the facility bill is Part A but the doctor who treats you bills under Part B.