Full Definition

Medicare Part B coinsurance: After meeting the annual deductible, Medicare covers 80% of the Medicare-approved amount for most Part B services. The beneficiary pays 20% coinsurance. Because there is no out-of-pocket maximum in Original Medicare, a serious illness generating $100,000 in Part B charges would result in $20,000 in patient coinsurance — a major financial risk.

SNF coinsurance: For skilled nursing facility stays days 21-100, the daily copayment is ~$194.50 in 2024 (adjusted annually). Days 1-20 are covered at 100% (after the Part A deductible). 100 days is the maximum covered per benefit period; there is no coverage for long-term custodial SNF care.

Medigap plans cover most or all Medicare coinsurance and copayments, providing cost predictability. Medicare Advantage plans have their own copayment structures that vary by plan and service type.