Uninsured and Underinsured Medical Service Options

An estimated 25.6 million Americans under age 65 had no health insurance in 2022, according to the U.S. Census Bureau's Current Population Survey. Millions more carry coverage that leaves them facing deductibles, copays, and coverage gaps that can make a routine hospitalization financially catastrophic. This page maps the landscape of services, programs, and frameworks that exist specifically for people who fall outside — or fall through — standard insurance coverage. The options are more structured than most people expect, and understanding where they sit in the regulatory framework changes how effectively someone can use them.

Definition and Scope

"Uninsured" has a precise meaning in federal reporting: no private insurance, no Medicare, no Medicaid, no military coverage, and no Indian Health Service coverage at any point during the measurement period. "Underinsured" is trickier. The Commonwealth Fund defines underinsured adults as those whose out-of-pocket costs over 12 months equaled at least 10 percent of household income — or 5 percent for lower-income households — or whose deductible alone represented that threshold. That distinction matters because the underinsured are often invisible in discussions that focus only on enrollment numbers.

The federal government recognizes both populations through a constellation of programs administered across the Health Resources and Services Administration (HRSA), the Centers for Medicare & Medicaid Services (CMS), and state Medicaid agencies. These programs operate under statutory authority granted by the Public Health Service Act, the Affordable Care Act, and the Social Security Act — not as charitable gestures, but as codified obligations with defined eligibility criteria. The regulatory context for medical services that governs these programs shapes what providers can charge, how billing must be structured, and what rights patients hold regardless of payment status.

Scope-wise, the uninsured and underinsured problem concentrates in predictable places: working-age adults between 26 and 64, self-employed individuals, workers in industries without employer-sponsored coverage, and households that fall into the Medicaid expansion gap in states that did not participate. As of 2023, 10 states had not adopted Medicaid expansion under the ACA, according to KFF's State Health Facts tracker.

How It Works

Access to subsidized or free care for uninsured and underinsured patients generally flows through one of four distinct delivery channels:

1. Federally Qualified Health Centers (FQHCs): HRSA-designated primary care facilities required by law (42 U.S.C. § 254b) to serve all patients regardless of ability to pay. FQHCs use a sliding fee scale tied to the Federal Poverty Level — patients at or below 100% FPL typically pay nothing, and charges scale upward to a capped maximum. There are more than 1,400 FQHC organizations operating roughly 14,000 service delivery sites nationwide, per HRSA's 2022 Uniform Data System report.

2. Hill-Burton Obligation Facilities: Hospitals and other facilities that received federal construction funds under the Hill-Burton Act of 1946 carry an ongoing obligation to provide a defined volume of free or reduced-cost care. The Health Resources and Services Administration maintains the active list of obligated facilities.

3. Medicaid and CHIP Emergency and Presumptive Eligibility: Even in states with restrictive Medicaid rules, federal law requires coverage of emergency services for individuals who meet income criteria. Pregnant women, children, and certain other groups may qualify for presumptive eligibility — a temporary coverage period while a formal application processes.

4. Hospital Charity Care Programs: Nonprofit hospitals operating under 501(c)(3) status are required by the Affordable Care Act (Section 501(r) of the Internal Revenue Code) to maintain written financial assistance policies, limit charges to the amounts generally billed to insured patients, and prohibit extraordinary collection actions before determining whether a patient qualifies for assistance. The IRS enforces this requirement through Form 990, Schedule H.

For the underinsured specifically, cost-sharing reduction subsidies under the ACA marketplace system and Medicaid coverage of medical services can close gaps — but only within the coverage structure of plans already held.

Common Scenarios

The population without adequate coverage is not monolithic, and the right access pathway depends heavily on clinical context. Three scenarios illustrate how the infrastructure actually sorts out:

Acute, time-sensitive care: EMTALA — the Emergency Medical Treatment and Labor Act — requires hospital emergency departments that accept Medicare (virtually all of them) to provide a medical screening examination and stabilizing treatment to any patient regardless of insurance status or ability to pay. EMTALA does not cap costs; it mandates screening and stabilization only. The resulting bill may be substantial, which is where hospital charity care policies under 501(r) become relevant. Patients who pursue a financial assistance application within the window established by the hospital's written policy — typically 240 days from the first billing statement, per IRS guidance — are protected from most extraordinary collection actions during that period.

Ongoing primary and preventive care: This is where FQHCs do the heaviest lifting. Preventive medical services including cancer screenings, vaccinations, and chronic disease management are available on the sliding scale. Federally qualified centers also integrate behavioral health and dental services at a significant portion of sites, addressing the kind of fragmented access that makes health disparities in medical services self-reinforcing.

Mental health and substance use services: Community Mental Health Centers (CMHCs) hold a parallel federal designation to FQHCs and serve uninsured patients under similar sliding-fee obligations. Coverage for mental health medical services for low-income uninsured individuals also flows through block grants administered under SAMHSA — the Substance Abuse and Mental Health Services Administration — via the Community Mental Health Services Block Grant program.

Decision Boundaries

Navigating these options requires clarity about two variables: income relative to the Federal Poverty Level, and the urgency and type of care needed. The table below maps these axes structurally.

The critical decision point for most uninsured individuals is whether income falls below 100% FPL in a non-expansion state — that gap population receives no ACA subsidy and no Medicaid coverage, making FQHC access and charity care the primary structural safeguard. For the underinsured, the 501(r) financial assistance application — often underused because patients assume denial — is the most directly applicable mechanism. Detailed breakdowns of eligibility by population are covered in medical services for low-income individuals and medical services for uninsured patients.

Where telehealth and virtual medical services intersect with this landscape is increasingly significant: HRSA-funded health centers are authorized to deliver telehealth services that count toward their sliding-scale obligations, extending geographic reach at lower per-visit cost — a structural shift that matters considerably in rural and underserved areas.