The Federal-State Medicaid Partnership
Medicaid is a joint federal-state program providing healthcare coverage to eligible low-income individuals, established under Title XIX of the Social Security Act. Unlike Medicare, which operates under uniform federal rules nationwide, Medicaid is administered by individual states within broad federal guidelines, resulting in significant variation in eligibility criteria, covered benefits, and reimbursement methodology from state to state.
Eligibility
Medicaid eligibility traditionally covers specific categories including low-income children, pregnant women, elderly individuals, and people with disabilities. The Affordable Care Act allowed states to expand Medicaid eligibility to nearly all adults below a specified income threshold, though states retain the option whether to adopt this expansion, resulting in coverage gaps for low-income adults in non-expansion states.
Traditional Medicaid Eligibility Categories
- Low-income children and their parents
- Pregnant women meeting income requirements
- Elderly individuals, often those also eligible for Medicare
- Individuals with qualifying disabilities
- Adults covered under state Medicaid expansion, where adopted
Federal and State Funding Structure
Medicaid funding is shared between federal and state governments through the Federal Medical Assistance Percentage, which determines the federal share of program costs based on a state's per capita income relative to the national average, meaning states with lower average incomes receive a higher federal matching rate.
Fee-for-Service Reimbursement
Under traditional fee-for-service Medicaid, providers bill the state Medicaid agency directly for services rendered, with reimbursement rates set by each state, often lower than corresponding Medicare or commercial payer rates.
Medicaid Managed Care
The majority of Medicaid beneficiaries nationwide are now enrolled in managed care arrangements, where states contract with managed care organizations to coordinate and pay for enrollee care in exchange for a capitated per-member-per-month payment. Managed care aims to control costs and improve care coordination compared to traditional fee-for-service arrangements.
Waivers
States may apply for federal waivers, such as Section 1115 demonstration waivers, allowing flexibility to test innovative approaches to eligibility, benefits, or delivery systems outside standard federal Medicaid rules, often used to implement work requirements, alternative benefit packages, or expanded home and community-based services.
Encounter Data
Under managed care arrangements, states require managed care organizations to submit detailed encounter data documenting every service provided to enrollees, even though the state does not directly pay individual claims. Encounter data supports program oversight, quality measurement, and accurate capitation rate setting, making complete and accurate coding and documentation just as critical under managed care as under fee-for-service billing.