Original Medicare: Parts A and B Explained
When most people talk about "Original Medicare," they mean Medicare Part A and Medicare Part B. Together, these two parts form the foundation of federal health insurance for people 65 and older — and for certain younger individuals with qualifying disabilities. Understanding exactly what each part covers helps you plan for out-of-pocket costs and decide whether you need additional coverage.
Medicare Part A: Hospital Insurance
Part A is often called hospital insurance because it primarily covers inpatient care. Most people do not pay a monthly premium for Part A if they (or their spouse) worked and paid Medicare taxes for at least 10 years (40 quarters).
What Part A Covers
- Inpatient hospital care — semi-private room, meals, nursing care, and general hospital services during a covered stay
- Skilled nursing facility (SNF) care — following a qualifying hospital stay of at least 3 days, for up to 100 days per benefit period
- Home health care — part-time skilled nursing care and therapy services when you are homebound
- Hospice care — for individuals with a terminal illness and a life expectancy of 6 months or less
- Inpatient mental health care — up to 190 days in a psychiatric facility over a lifetime
What Part A Does NOT Cover
- Long-term custodial care (help with daily activities like bathing or dressing)
- Private-duty nursing
- A private room (unless medically necessary)
- Personal comfort items
Medicare Part B: Medical Insurance
Part B covers outpatient medical services — the care you receive outside of a hospital. Most beneficiaries pay a standard monthly premium for Part B, which is adjusted each year by the Centers for Medicare & Medicaid Services (CMS).
What Part B Covers
- Doctor visits — visits to your primary care physician and specialists
- Preventive services — annual wellness visits, flu shots, cancer screenings (mammograms, colonoscopies), cardiovascular screenings, and more
- Outpatient surgery and procedures
- Durable medical equipment (DME) — wheelchairs, walkers, blood sugar monitors, and oxygen equipment
- Mental health services — outpatient therapy and psychiatric evaluations
- Ambulance services — when other transportation would endanger your health
- Clinical lab tests — blood tests, urinalysis, and certain other diagnostic tests
- Physical, occupational, and speech therapy
- Home health care — when not covered by Part A
What Part B Does NOT Cover
- Routine dental, vision, and hearing care
- Prescription drugs (covered by Part D or Medicare Advantage)
- Cosmetic surgery
- Routine foot care (with some exceptions for diabetic patients)
- Acupuncture (limited exceptions may apply)
How Part A and Part B Work Together
Parts A and B complement each other. For example, if you are hospitalized (Part A), your doctor's visits while you're in the hospital may be billed under Part B. You'll generally be responsible for a deductible and coinsurance for both parts.
| Coverage Area | Part A | Part B |
|---|---|---|
| Hospital inpatient stays | ✓ | |
| Doctor and specialist visits | ✓ | |
| Skilled nursing facility | ✓ | |
| Outpatient surgery | ✓ | |
| Preventive screenings | ✓ | |
| Home health care | ✓ | ✓ |
| Hospice | ✓ |
Gaps in Original Medicare Coverage
Original Medicare does not cover everything. Notable gaps include dental, vision, hearing aids, and most prescription drugs. Many beneficiaries choose to add a Medicare Supplement (Medigap) policy or enroll in a Medicare Advantage plan to help fill these gaps and manage out-of-pocket costs.
Understanding the boundaries of Parts A and B empowers you to make smarter decisions about supplemental coverage and budget effectively for your healthcare needs.