Medicaid: Eligibility, Covered Services, and State Variations

Medicaid covers more than 90 million Americans — roughly 1 in 4 people in the country — making it the single largest source of health coverage by enrollment (CMS Medicaid Enrollment Data). It is a joint federal-state program, which means the rules shift considerably depending on where someone lives. This page covers who qualifies, what the program actually pays for, and how state-level decisions create meaningful differences in access and benefits. Understanding Medicaid matters not just for the 90 million enrolled, but for anyone navigating healthcare coverage options in the United States.

Definition and scope

Medicaid is a means-tested public insurance program, jointly funded by the federal government and individual states, established in 1965 under Title XIX of the Social Security Act. The federal government sets a floor — mandatory minimum standards for eligibility and covered services — and states operate within (and often expand upon) those requirements.

The program does not serve a single population. Medicaid covers low-income adults, children, pregnant people, elderly individuals, and people with disabilities. Each of those groups can have different eligibility pathways, cost-sharing rules, and benefit packages — sometimes within the same state.

A feature that often surprises people: Medicaid is also the dominant payer for long-term care options in the United States. It funds roughly 42% of total long-term services and supports spending nationally (KFF Medicaid and Long-Term Care), meaning nursing home care for a middle-class family can become a Medicaid question faster than most people expect.

How it works

Federal law requires states to cover certain "mandatory" populations and services. Beyond that floor, states choose whether to expand eligibility, add optional benefit categories, or design their delivery systems through managed care contracts.

Federal mandatory coverage groups include:

1. Adults under 65 with incomes at or below 138% of the federal poverty level — but only in states that accepted the Affordable Care Act Medicaid expansion

That last point is load-bearing. As of 2024, 10 states had not adopted the ACA Medicaid expansion (KFF State Health Coverage Tracker), leaving a "coverage gap" where adults earn too much for traditional Medicaid but too little to qualify for marketplace subsidies.

Mandatory services — those every state must cover — include inpatient and outpatient hospital services, physician services, laboratory and X-ray services, nursing facility services, home health services, and preventive care and screenings for children under the Early and Periodic Screening, Diagnostic and Treatment (EPSDT) benefit.

Optional services — which states may choose to cover — include prescription drugs (covered by all 50 states in practice, but technically optional), dental care for adults, vision services, physical therapy, and mental health services beyond what federal parity law requires.

Most Medicaid beneficiaries receive care through managed care organizations (MCOs) — private insurers contracted by states to coordinate benefits. This arrangement shifts risk to the MCO and gives states a more predictable budget, but it adds a layer of administration between patients and providers.

Common scenarios

A few situations illustrate where Medicaid becomes the operative question:

Low-income adult in an expansion state. A 34-year-old with an annual income of $20,000 living in California would typically qualify for Medicaid under expansion rules, with minimal or no premiums and low cost-sharing. The same person living in Texas, which has not expanded Medicaid, likely would not qualify unless they had dependent children — and might fall into the coverage gap described in uninsured and underinsured Americans.

Elderly person requiring nursing home care. An 82-year-old who has depleted personal savings on care costs can "spend down" to meet Medicaid asset limits and qualify for nursing facility coverage. This is one of the more consequential — and least publicly discussed — aspects of Medicaid's role in long-term care.

Child in a CHIP household. Children in families earning too much for Medicaid but below roughly 200–300% of the federal poverty level (the threshold varies by state) may qualify for the Children's Health Insurance Program, which operates as a companion to Medicaid and shares much of its administrative infrastructure.

Dual-eligible individuals. Approximately 12.5 million people qualify for both Medicaid and Medicare simultaneously (CMS Medicare-Medicaid Coordination). Medicaid typically wraps around Medicare to cover premiums, cost-sharing, and services Medicare does not include — making coordination between the two programs a significant administrative challenge.

Decision boundaries

The clearest dividing line in Medicaid is the expansion/non-expansion divide. In the 40 states (plus Washington D.C.) that have expanded Medicaid, coverage extends to adults with incomes up to 138% of the federal poverty level. In non-expansion states, eligibility for adults without dependent children is often effectively zero.

Beyond that, states differ on:

• Income thresholds for parents and caretakers (ranging from below 20% of the federal poverty level in some states to over 100% in others)
• Asset tests — some states have eliminated asset limits for working-age adults; most retain them for elderly and disability pathways
• Covered services — adult dental coverage exists in some states and not in others; substance use disorder treatment depth varies significantly
• Managed care vs. fee-for-service — rural states in particular may rely more heavily on fee-for-service models given limited MCO infrastructure, a tension explored in detail at rural healthcare challenges

What Medicaid provides, and to whom, is ultimately a policy choice replicated 50 times over — which is what makes it one of the most consequential, and most geographically unequal, features of the US healthcare landscape.