Parts of Medicare Explained (A, B, C, D)

Medicare has four parts that work together to provide coverage. Here's what each one covers and how they fit into your overall health plan.

Part A: Hospital Insurance

Part A covers inpatient hospital stays, skilled nursing facility care (following a hospital stay), hospice care, and some home health services. Most people don't pay a premium for Part A if they or their spouse paid Medicare taxes while working.

Part A has a deductible ($1,736 per benefit period in 2026) and covers up to 90 days of hospital care per benefit period, plus a lifetime reserve of 60 additional days. After that, you pay all costs.

Part B: Medical Insurance

Part B covers doctor visits, outpatient care, preventive services, medical equipment, and some home health services. You pay a monthly premium (2026: $202.90), an annual deductible (2026: $283), and typically 20% coinsurance for most services.

Higher earners pay more for Part B through Income-Related Monthly Adjustment Amounts (IRMAA). If your modified adjusted gross income exceeds certain thresholds, your premium increases.

Part C: Medicare Advantage Plans

Part C is an alternative to Original Medicare (Parts A and B). Private insurance companies offer these plans, which must cover everything Original Medicare covers—and often include extras like dental, vision, hearing, and prescription drug coverage.

Medicare Advantage plans typically have lower premiums but use provider networks (HMO/PPO) and may require referrals. You still pay your Part B premium plus any additional plan premium.

Part D: Prescription Drug Coverage

Part D adds prescription drug coverage to Original Medicare or certain Medicare Advantage plans. You pay a monthly premium (varies by plan), an annual deductible (up to $590 in 2026), and copays or coinsurance for medications.

If you don't enroll in Part D when first eligible and don't have creditable drug coverage elsewhere, you'll pay a late enrollment penalty for as long as you have Part D. The penalty increases the longer you wait.