What Are the Different Medicare Plans? Parts A, B, C, D, Medigap

Medicare is built from four parts. Part A is hospital insurance, Part B is medical insurance for outpatient care, Part C (Medicare Advantage) is a private plan that bundles A and B and usually drug coverage together, and Part D is standalone prescription drug coverage. A separate product, Medigap, pairs with Original Medicare to fill in deductibles and coinsurance. Here is what Medicare Parts A, B, C, and D each cover, what they cost in 2026, and how they fit together.

Part A: Hospital Insurance

Part A pays for inpatient hospital stays, skilled nursing facility care after a qualifying hospital admission, hospice care for terminal illness, and some home health services. Most people pay no monthly premium because they or a spouse paid Medicare taxes for at least 10 years (40 quarters of work). Without that work history, the 2026 premium runs up to $565 per month, or $311 with 30 to 39 quarters.¹

Premium-free doesn’t mean cost-free. Each benefit period starts with a $1,736 deductible in 2026.² A benefit period begins the day you’re admitted as an inpatient and ends after you’ve been out of the hospital or skilled nursing facility for 60 straight days. Nothing limits how many benefit periods you can have in a year, and each one restarts the deductible.³

Daily hospital coinsurance in 2026:

Days 1–60: $0
Days 61–90: $434 per day
Days 91–150: $868 per day, drawn from a one-time pool of 60 lifetime reserve days
After day 150: you pay all costs

Lifetime reserve days do not renew. Once you’ve used all 60 across your lifetime, any hospitalization past day 90 in a benefit period is entirely on you.³

Skilled nursing facility coverage has its own structure. Part A covers days 1 through 20 at no daily cost after the hospital deductible. Days 21 through 100 carry $217 per day in coinsurance in 2026. Coverage stops entirely after day 100, and you must have had a qualifying three-day inpatient hospital stay to trigger the benefit at all.⁴

Part B: Medical Insurance

Part B covers outpatient care: doctor visits, lab tests, preventive screenings, durable medical equipment like wheelchairs, mental health services, and ambulance transportation. Nearly everyone pays a monthly premium. In 2026, the standard premium is $202.90.⁵ Higher-income beneficiaries pay a surcharge on top; see IRMAA below.

The 2026 Part B annual deductible is $283.⁵ After that, Medicare generally pays 80% of the approved amount for covered services and you owe the other 20%. Under Original Medicare, that 20% has no annual ceiling, which is the reason many people add either Medigap or Medicare Advantage.

Part B is technically voluntary. But if you delay enrollment without other creditable coverage, you’ll pay a permanent penalty of 10% added to your premium for every full 12-month period you could have signed up.⁶ That surcharge never goes away.

What Original Medicare Does Not Cover

The gaps catch people off guard more than the coverage itself. Parts A and B do not pay for routine dental care, dentures, routine eye exams for glasses or contacts, hearing exams for hearing aids, or most routine foot care.⁷

Long-term custodial care is the biggest exclusion. Medicare does not cover nursing home stays when the need is help with daily activities like bathing, dressing, or eating. It pays only for short-term skilled nursing after a qualifying hospital stay. For ongoing personal-care assistance you’ll need Medicaid, long-term care insurance, or private funds.⁷

And Original Medicare has no annual out-of-pocket maximum. A catastrophic year of hospitalizations or expensive outpatient treatment can leave you owing tens of thousands in Part B coinsurance alone. Medicare Advantage and Medigap each solve that problem, in different ways.

Part C: Medicare Advantage

Medicare Advantage is the private-plan alternative to Original Medicare. Private insurers contract with the federal government to deliver all Part A and Part B benefits in a single plan, and most also include Part D drug coverage. You must have both Part A and Part B to enroll, and you keep paying the Part B premium to the government. Many plans charge an additional monthly premium; some charge nothing extra.

The main draw is the extras. Most plans include routine dental, vision, and hearing benefits Original Medicare skips. Some offer gym memberships, transportation to medical appointments, or over-the-counter drug allowances. Every Medicare Advantage plan must cover at least everything Original Medicare covers, but plans have wide latitude to set copays, coinsurance, and networks.⁸

The other major difference: every Medicare Advantage plan must set an annual out-of-pocket maximum. In 2026, the CMS-mandated ceiling for in-network services is $8,000. Once you hit that limit, the plan pays 100% of covered services for the rest of the year.

Network Types

Most plans use provider networks, and the network type controls how much flexibility you have. An HMO restricts you to in-network doctors and hospitals except in emergencies and usually requires a referral to see a specialist. A PPO lets you go out of network at higher cost-sharing and does not require referrals. Some plans use Private Fee-for-Service or Medical Savings Account structures, but HMOs and PPOs account for most enrollment.

Special Needs Plans

Medicare Advantage also includes Special Needs Plans for specific populations: Dual Eligible SNPs for people who qualify for both Medicare and Medicaid, Chronic Condition SNPs for people with conditions like diabetes, heart failure, or end-stage renal disease, and Institutional SNPs for people who live in or need nursing-facility-level care.⁹ Their benefits, networks, and care coordination are built around the enrolled population.

CMS rates every Medicare Advantage plan on a 1-to-5 star scale each year for things like preventive care, chronic disease management, customer service, and member complaints. Plans with 4 or more stars receive bonus payments that they often reinvest in extra benefits. You can check any plan’s star rating on Medicare.gov before enrolling.

Part D: Prescription Drug Coverage

Part D is the prescription drug benefit, delivered entirely through private insurance companies. You can get it two ways: as a standalone drug plan paired with Original Medicare, or built into a Medicare Advantage plan. The federal government subsidizes these plans to keep premiums lower than they otherwise would be.

The national base beneficiary premium for Part D in 2026 is $38.99.¹⁰ That’s a reference figure used for penalty calculations, not what you’ll actually pay. Your real premium depends on the plan you pick.

Drug costs move through three phases each calendar year:¹¹

Deductible stage: you pay all drug costs until you reach the plan’s deductible. No Part D plan can set its deductible higher than $615 in 2026, and many have none.
Initial coverage: you pay 25% coinsurance for both generics and brand-name drugs until your out-of-pocket spending reaches $2,100.
Catastrophic coverage: after $2,100 in out-of-pocket spending, you pay $0 for covered drugs for the rest of the year.

The $2,100 annual cap is new-generation Part D. Before the Inflation Reduction Act redesign, beneficiaries hit a coverage gap and then paid 5% coinsurance in catastrophic coverage with no ceiling. Now there’s a hard annual ceiling on drug spending.¹² If you face high drug costs early in the year, the Medicare Prescription Payment Plan lets you spread the out-of-pocket portion across the remaining months rather than paying it all at the pharmacy counter.¹³

Every Part D plan uses a formulary that sorts covered drugs into tiers, with generics at the lowest cost-sharing and specialty drugs at the highest. Plans must cover at least two drugs in every therapeutic category that are not therapeutically equivalent.¹⁴ Formularies change each year, so review your plan’s drug list during open enrollment.

If you go 63 or more consecutive days without Part D or other creditable drug coverage, a permanent late enrollment penalty kicks in: 1% of the national base beneficiary premium for every month you were without coverage, added to your premium for life. At 2026 rates that’s about $0.39 per uncovered month.⁶

Medigap: Medicare Supplement Insurance

Medigap policies are sold by private insurers to cover the deductibles, coinsurance, and copayments Original Medicare leaves behind. Ten standardized plan types are labeled A through N. Federal law requires that every plan with the same letter offers identical benefits regardless of which company sells it, so a Plan G from one insurer covers exactly what a Plan G from another does.¹⁵ What differs is the premium.

Medigap and Medicare Advantage are mutually exclusive. You cannot hold both at once. Medigap works only alongside Original Medicare and includes no prescription drug coverage; if you want drug coverage with Medigap, you’ll need a standalone Part D plan.

Plan G and Plan N are the most popular choices for people newly eligible. Plan G covers nearly all out-of-pocket costs except the annual Part B deductible ($283 in 2026). Plan N costs less but requires small copayments for some office visits and for emergency room trips that don’t lead to an inpatient admission. Under the Medicare Access and CHIP Reauthorization Act of 2015, anyone newly eligible for Medicare on or after January 1, 2020 cannot buy Plan C or Plan F, both of which covered the Part B deductible. If you were eligible before that date, you can still buy them.

Timing matters. Your best window is the six-month Medigap open enrollment period that starts the month you turn 65 and are enrolled in Part B. During this window, insurers cannot deny you a policy or charge more because of pre-existing conditions.¹⁵ After that, insurers in most states can use medical underwriting and may refuse to sell you a policy or price it based on your health history.

Higher Premiums at Higher Incomes (IRMAA)

If your income exceeds certain thresholds, you’ll pay more than the standard premium for both Part B and Part D. The surcharge is called the Income-Related Monthly Adjustment Amount, and it’s based on your modified adjusted gross income from two years earlier; for 2026, that means your 2024 tax return.⁵

In 2026, individuals filing separately pay no surcharge with income of $109,000 or less. Above that, the Part B surcharge ranges from $81.20 to $487.00 per month across five brackets, topping out at $500,000 or more in income. Married couples filing jointly have double the income thresholds. Part D carries its own IRMAA on the same income brackets, ranging from $14.50 to $91.00 per month on top of whatever your plan charges.⁵

If your income has dropped since the tax year being used, you can file Form SSA-44 to request a reduction. Qualifying life-changing events include retirement, the death of a spouse, divorce, or an involuntary loss of income-producing property.¹⁶

Help for Lower-Income Beneficiaries

Medicare has two categories of financial help that many eligible people never apply for. Medicare Savings Programs help with Part A and Part B costs; Extra Help (the Low-Income Subsidy) reduces Part D drug expenses.

Three state-administered Medicare Savings Programs pay some or all of your premiums, deductibles, and coinsurance depending on income and resources. The Qualified Medicare Beneficiary program is the most generous, covering Part A and Part B premiums, deductibles, coinsurance, and copayments. The Specified Low-Income Medicare Beneficiary and Qualifying Individual programs each pay the Part B premium at slightly higher income limits.¹⁷ Apply through your state Medicaid office, not through Medicare.

Extra Help dramatically reduces Part D premiums, deductibles, and copayments. Resource limits for full Extra Help in 2026 are $16,590 for an individual and $33,100 for a married couple.¹⁸ Qualifying beneficiaries may pay as little as $1.60 for generics and $4.90 for brand-name drugs per prescription. Apply through Social Security or your state Medicaid office.

Enrollment Periods and Late Penalties

Getting the timing right is one of the most consequential parts of Medicare. Miss a deadline and you may go months without coverage or pay permanent premium increases.

Initial Enrollment Period

Your first chance is a seven-month window that starts three months before the month you turn 65, includes your birthday month, and ends three months after.¹⁹ If you’re already receiving Social Security retirement benefits, you’ll be enrolled in Parts A and B automatically. Otherwise, sign up through the Social Security Administration online at ssa.gov or at a local office.

Annual Election Period

From October 15 through December 7 each year, you can switch between Original Medicare and Medicare Advantage, change your Medicare Advantage plan, or join, switch, or drop a standalone Part D plan.²⁰ Changes take effect January 1.

Medicare Advantage Open Enrollment

From January 1 through March 31, people already enrolled in a Medicare Advantage plan can switch to a different Medicare Advantage plan or drop back to Original Medicare and pick up a standalone Part D plan. You get one change during this period, and coverage starts the month after the plan receives your request.

General Enrollment Period

If you missed your Initial Enrollment Period and don’t qualify for a Special Enrollment Period, you can sign up for Part A and Part B between January 1 and March 31 each year. Coverage starts the month after you sign up, and late enrollment penalties will likely apply.²¹

Special Enrollment Period

If you delayed Medicare because you had group health coverage through your own or a spouse’s current employer, you qualify for a Special Enrollment Period once that coverage ends. You can enroll in Part B without penalty within eight months. Submit Form CMS-40B along with Form CMS-L564, which your employer completes to verify your coverage dates.²²

What the Penalties Cost

The Part B penalty adds 10% to your standard monthly premium for every full 12-month period you were eligible but didn’t enroll and didn’t have qualifying employer coverage. Wait two years, and you pay 20% more than the standard premium for the rest of your time on Medicare.⁶ The Part D penalty adds 1% of the national base beneficiary premium per uncovered month; a 14-month gap adds roughly $5.50 to your monthly premium permanently. Part A also has a penalty for people who must pay a premium: a 10% surcharge for twice the number of years they could have been enrolled but weren’t. Signing up during a valid Special Enrollment Period is the main way to legitimately avoid all three.

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