Understanding What Medicare Covers

One of the most common questions new Medicare beneficiaries ask is: "What exactly will Medicare pay for?" The answer depends on which parts of Medicare you have, but Original Medicare (Parts A and B) provides broad coverage for medically necessary services. Here's a comprehensive breakdown.

What Medicare Part A Covers

Part A focuses on care provided in institutional settings:

  • Inpatient hospital care: Semi-private room, meals, nursing care, medications administered during your stay, and operating/recovery room costs.
  • Skilled nursing facility (SNF) care: Covered up to 100 days per benefit period, following a qualifying 3-day inpatient hospital stay. Full coverage applies for the first 20 days; days 21–100 require a co-insurance payment.
  • Hospice care: Pain relief, symptom management, and support services for people with a terminal illness and a life expectancy of six months or less.
  • Home health care: Medically necessary part-time skilled nursing, physical therapy, speech-language pathology, and occupational therapy — but only if you are homebound.

What Medicare Part B Covers

Part B is broader in scope and covers two main categories:

Medically Necessary Services

  • Doctor and specialist visits
  • Outpatient hospital services and emergency room visits
  • Ambulance services
  • Mental health care (inpatient and outpatient)
  • Substance use disorder treatment
  • Durable medical equipment (blood sugar monitors, walkers, CPAP machines, etc.)
  • Clinical laboratory services
  • Chemotherapy and radiation therapy (outpatient)
  • Kidney dialysis

Preventive Services

Medicare Part B places a strong emphasis on prevention. Covered preventive services include:

  • Annual Wellness Visit (free once per year)
  • Cardiovascular disease screenings
  • Colorectal cancer screenings (colonoscopy, stool tests)
  • Mammograms and cervical cancer screenings
  • Diabetes screenings and self-management training
  • Bone density measurements
  • Flu, pneumococcal, COVID-19, and hepatitis B vaccines
  • Depression screening
  • Obesity counseling

What Medicare Part D Covers

Part D covers outpatient prescription drugs. Each plan maintains a formulary — a list of covered medications divided into cost tiers. Generally covered categories include:

  • Brand-name and generic prescription drugs
  • Some vaccines not covered under Part B

Part D does not cover drugs administered in a hospital or clinic setting (those are typically covered under Part A or B).

What Medicare Does NOT Cover

Understanding Medicare's gaps is just as important as knowing what it covers. Original Medicare does not cover:

  • Routine dental care — cleanings, fillings, dentures (except in limited circumstances)
  • Routine vision care — eye exams for glasses or contact lenses, eyeglasses, contacts
  • Hearing aids and routine hearing exams
  • Long-term custodial care — assistance with daily activities like bathing and dressing (not skilled medical care)
  • Cosmetic surgery
  • Most care received outside the United States
  • Acupuncture (except for chronic low back pain, which is now covered)

Many of these gaps can be addressed through a Medicare Advantage plan, which often bundles dental, vision, and hearing benefits, or a Medigap supplemental policy for help with cost-sharing.

How to Verify Coverage for a Specific Service

If you're unsure whether a particular service is covered, you have a few options:

  1. Visit Medicare.gov and use the "What's Covered" tool.
  2. Call Medicare directly at 1-800-MEDICARE (1-800-633-4227).
  3. Ask your doctor's office to verify coverage before your appointment.
  4. Review your plan's Evidence of Coverage document if you have Medicare Advantage.

Knowing your benefits in advance helps you avoid unexpected bills and make the most of the coverage you've earned.