Original Medicare
The traditional fee-for-service Medicare program administered directly by the federal government under Parts A and B, with no network restrictions but no built-in cap on out-of-pocket costs.
Original Medicare is the federal health insurance program established by Title XVIII of the Social Security Act (1965). Under Original Medicare, beneficiaries can see any physician or hospital that accepts Medicare assignment — approximately 93% of active physicians — with no network requirement, no referral needed for specialists, and coverage in any US state. This flexibility is particularly valued by retirees who winter in different states or travel frequently.
The critical weakness of Original Medicare is the absence of an out-of-pocket maximum. Medicare pays 80% of approved amounts for Part B services indefinitely; the remaining 20% coinsurance accumulates without a cap. A major cancer treatment or cardiac surgery generating $500,000 in Medicare-approved charges would leave the beneficiary responsible for $100,000+ in 20% coinsurance — typically the reason beneficiaries add a Medigap supplement or choose Medicare Advantage.
Original Medicare's annual cost is determined primarily by the Part B premium ($174.70/month standard in 2024, higher for IRMAA filers), any Part D drug plan premium, and actual utilization of services. Beneficiaries who are healthy and rarely use care may spend far less annually with Original Medicare plus a low-cost Part D plan than with a comprehensive Medigap bundle.
Real-World Example
A healthy 67-year-old with Original Medicare plus a $25/month Part D plan and no Medigap spent $2,396/year in Medicare costs — $1,692 less than the Plan G alternative — but carried unlimited exposure to 20% coinsurance if a serious illness developed.