Basic Medicare, officially called Original Medicare, is a two-part federal health insurance program. Part A covers hospital and inpatient care. Part B covers doctor visits, outpatient services, and preventive care. Together they handle a broad range of medical needs, but they leave some significant gaps, including prescription drugs, dental work, and vision care.
Who Qualifies for Medicare
Most people become eligible at age 65 if they or a spouse paid Medicare taxes for at least 10 years (40 quarters) of work. You can also qualify before 65 if you’ve received Social Security disability benefits for 24 months. People with permanent kidney failure needing regular dialysis or a kidney transplant can enroll at any age, provided they or a spouse meet certain work history requirements.
If you qualify through work history, Part A is premium-free. If not, you can buy into it: $285 per month in 2025 with at least 30 quarters of work, or $518 per month with fewer than 30. Part B carries a standard monthly premium of $185 in 2025, regardless of work history.
Part A: Hospital and Inpatient Care
Part A is your hospital insurance. It covers inpatient hospital stays, skilled nursing facility care, hospice care, and some home health care. When you’re admitted to a hospital as an inpatient (which requires a formal doctor’s order), Medicare pays for a semi-private room, meals, general nursing, medications administered during your stay, and other hospital services tied to your treatment.
What it won’t pay for: a private room (unless medically necessary), private-duty nursing, or personal items like razors and slippers. Phone and TV charges are also excluded if billed separately.
How Hospital Costs Work
Part A uses a “benefit period” system rather than a calendar year. A benefit period starts the day you’re admitted as an inpatient and ends once you’ve been out of the hospital (and out of skilled nursing) for 60 consecutive days. Each benefit period resets your cost-sharing but also resets your deductible.
In 2025, the Part A deductible is $1,676 per benefit period. After meeting that deductible, you pay nothing for the first 60 days. Days 61 through 90 cost $419 per day. Beyond 90 days, you draw on 60 lifetime reserve days at $838 per day. Once those are gone, you’re responsible for the full cost. Most hospital stays are well under 60 days, so many people only encounter the deductible.
Skilled Nursing Facility Care
Part A covers up to 100 days in a skilled nursing facility per benefit period, but only after a qualifying hospital stay of at least three consecutive days. The first 20 days are fully covered after your deductible. Days 21 through 100 carry a daily coinsurance of $209.50 in 2025. After day 100, Medicare stops paying.
This is skilled, short-term rehabilitation care, not long-term custodial care. If you need ongoing help with daily activities like bathing or dressing without a skilled medical need, Medicare does not cover it.
Hospice and Home Health
Part A covers hospice care for people with a terminal illness and a life expectancy of six months or less who choose comfort-focused treatment rather than curative care. Hospice benefits include pain management, nursing visits, counseling, and medications related to the terminal diagnosis. Part A also covers medically necessary home health services, such as intermittent skilled nursing or physical therapy, when ordered by a doctor.
Part B: Doctor Visits and Outpatient Services
Part B is your medical insurance for everything that happens outside a hospital admission. It covers doctor visits, outpatient procedures, lab tests, diagnostic imaging, ambulance services, mental health care, and medically necessary supplies. It also covers durable medical equipment you use at home: wheelchairs, walkers, canes, hospital beds, oxygen equipment, CPAP machines, glucose monitors with test strips and lancets, and similar items.
The annual Part B deductible in 2025 is $257. After that, you typically pay 20% of the Medicare-approved amount for most services, with Medicare covering the remaining 80%. There is no annual cap on your out-of-pocket spending under Original Medicare, which is one reason many people buy supplemental coverage.
Mental Health Services
Part B covers outpatient mental health care, including visits with psychiatrists, psychologists, and clinical social workers for conditions like depression and anxiety. You pay 20% of the Medicare-approved amount for these visits after your deductible. If you need inpatient psychiatric care, Part A covers it the same as other hospital stays, with one exception: treatment in a freestanding psychiatric hospital (rather than a general hospital’s psychiatric unit) is limited to 190 days over your lifetime.
Preventive Services at No Cost
Part B covers a long list of preventive services with no deductible and no coinsurance, as long as you see a provider who accepts Medicare assignment. This is one of the most valuable parts of basic Medicare, and many people don’t take full advantage of it.
Covered screenings include mammograms, colonoscopies and other colorectal cancer tests, lung cancer screenings, prostate cancer screenings, cardiovascular disease screenings, diabetes screenings, glaucoma tests, hepatitis B and C screenings, HIV screenings, bone density measurements, and depression screenings.
Medicare also covers a range of vaccines at no cost: flu shots, pneumococcal shots, COVID-19 vaccines, and hepatitis B shots. You get a one-time “Welcome to Medicare” preventive visit within your first 12 months of Part B enrollment, plus a yearly wellness visit after that. These annual visits are designed to create or update a personalized prevention plan, not to serve as a full physical exam (routine physicals are actually not covered).
Other no-cost preventive benefits include tobacco cessation counseling, alcohol misuse screening, obesity behavioral therapy, diabetes self-management training, medical nutrition therapy, and STI screenings with counseling.
What Original Medicare Does Not Cover
The gaps in basic Medicare are significant and catch many new enrollees off guard. Original Medicare does not cover:
- Most dental care: routine cleanings, fillings, tooth extractions, and dentures
- Vision: eye exams for prescription glasses and the glasses or contacts themselves
- Hearing aids and the exams required to fit them
- Long-term care: ongoing custodial help with daily living in a nursing home or at home
- Prescription drugs: medications you pick up at a pharmacy (with limited exceptions)
- Routine physical exams (the yearly wellness visit is covered, but a comprehensive physical is different)
- Cosmetic surgery and massage therapy
- Care from providers who have opted out of Medicare (except in emergencies)
These exclusions are why most Medicare beneficiaries add other coverage on top of Parts A and B.
Filling the Gaps: Part D and Medigap
Original Medicare has two common add-ons. Medicare Part D is a separate prescription drug plan you can purchase from a private insurer. It covers medications you fill at a pharmacy, which Parts A and B generally do not. Part B does cover a limited number of drugs, including insulin for pump users (capped at $35 per month’s supply) and medications administered in a doctor’s office, but everyday prescriptions require Part D.
Medigap (Medicare Supplement Insurance) is a private policy designed to cover some or all of the cost-sharing that Original Medicare leaves behind, like your 20% coinsurance under Part B, the Part A hospital deductible, and excess charges. Without Medigap or another form of supplemental coverage, there is no annual limit on what you can pay out of pocket under Original Medicare. A single extended hospital stay or a series of specialist visits can add up quickly.
Medicare Advantage (Part C) is an alternative to this whole setup. It bundles Parts A and B (and usually Part D) into a single plan from a private insurer, often with added dental, vision, and hearing benefits and a built-in out-of-pocket maximum. But it operates through provider networks and requires different trade-offs than Original Medicare with a Medigap policy.