NATIONAL INSURANCE GUIDE

Health Insurance in the U.S.

Health Insurance

Health Insurance in the United States: What You Need to Know

Health Insurance in the United States is the set of public programs and private contracts that pay for clinically necessary health care—hospital care, physician services, prescription drugs, mental-health treatment, maternity care, and related services. Unlike systems built around a single national health insurer, the U.S. arrangement is plural: coverage is obtained through employers, individual and family policies (including Marketplace plans), Medicare, Medicaid, the Children’s Health Insurance Program (CHIP), the military and veterans’ systems, and a residual uninsured population. Financing, eligibility, benefit design, and regulation differ across these channels, and coordination among them is often incomplete.

Coverage Snapshot (Recent Data)

According to the U.S. Census Bureau, 26.7 million people (7.9%) were uninsured for the full year in 2025; 311.2 million (92.1%) had coverage at some point during the year. Employer-sponsored insurance was the most common source (53.5% of people had it for at least part of the year), followed by Medicare (20.1%) and Medicaid (17.1%); direct-purchase coverage accounted for 10.5% and TRICARE for 2.8%.

The National Health Interview Survey (NCHS/CDC) estimated that 28.0 million people of all ages (8.3%) were uninsured at the time of interview in 2025; among adults ages 18–64 the rate was 11.6%.

KFF’s 2026 Employer Health Benefits Survey reports average annual premiums of about $9,804 for single coverage and $28,303 for family coverage (both up 5% from 2025). Covered workers contributed on average $7,471 toward family premiums (up 9%, or $621). Workers at smaller firms (fewer than 200 employees) contributed substantially more toward family coverage on average ($9,687) than workers at larger firms.

In the ACA Marketplaces, enhanced premium tax credits expired at the end of 2025. Effectuated enrollment fell from roughly 21.8 million in 2025 to about 19.2 million in 2026—the first decline in seven years. Average Marketplace deductibles rose sharply (KFF analysis: from about $2,759 in 2025 to $3,786 in 2026, a 37% increase), and plan selection shifted toward higher-deductible bronze plans (bronze share of selections rose from 30% to 40%; silver fell from 57% to 43%).

These figures change with policy, economic conditions, and survey method; always consult the latest Census, CMS, and KFF releases for current numbers.

Principal Sources of Coverage

Employer-sponsored insurance
The largest single source of coverage for the non-elderly. Employers offer group plans (fully insured or self-funded) and typically pay a substantial share of the premium. Plan design—deductible level, network type (HMO, PPO, EPO, POS), formulary, and out-of-pocket maximum—varies widely by firm size and industry. Self-funded plans are governed primarily by ERISA; fully insured plans are also subject to state insurance regulation. Dependent coverage, spousal rules, and waiting periods are set by the employer within legal limits.

Individual and Marketplace coverage
People without an affordable employer offer, and many self-employed and early retirees, purchase coverage in the individual market. Under the Affordable Care Act (ACA), plans sold on and off the Health Insurance Marketplace must cover essential health benefits, meet actuarial-value metal tiers (Bronze, Silver, Gold, Platinum), and observe guaranteed-issue and community-rating rules (with limited age and tobacco adjustments). Premium tax credits and cost-sharing reductions are available to eligible enrollees with Marketplace plans; the generosity and income range of those subsidies have been altered by legislation. Open enrollment is annual; special enrollment periods follow qualifying life events.

Medicare
Federal program primarily for people age 65 and older and for certain younger individuals with long-term disabilities or specific diagnoses. It comprises Part A (hospital insurance), Part B (medical insurance), Part C (Medicare Advantage—private plans that deliver Part A and B benefits, usually with Part D), and Part D (outpatient drugs). Cost-sharing in Original Medicare is significant; many beneficiaries add Medigap, employer retiree coverage, or Medicaid, or choose Medicare Advantage. Medicare does not comprehensively cover long-term custodial care, routine dental, vision, or hearing.

Medicaid and CHIP
Joint federal–state programs. Medicaid covers low-income children, pregnant women, adults (in expansion states), people with disabilities, and many long-term-care recipients. CHIP covers uninsured children in families with incomes above Medicaid thresholds. Eligibility, benefits, and delivery systems (fee-for-service versus managed care) vary by state. Dual eligibility with Medicare is common among low-income seniors and people with disabilities and creates complex coordination rules.

Military, veterans, and other public programs
TRICARE serves active-duty members, retirees, and families; VA health care serves eligible veterans; the Indian Health Service and certain other federal programs serve defined populations. These systems interact with Medicare, Medicaid, and private coverage when beneficiaries have dual or multiple entitlements.

Uninsured and underinsured
A residual share of the population remains uninsured or underinsured (high deductibles and narrow benefits relative to need). Rates vary by state, income, age, and immigration status. Uncompensated care, emergency-care mandates, and safety-net providers partially absorb the consequences.

Cost-Sharing Architecture

Most Health Insurance in the United States uses a combination of:

  • Premiums — periodic payments to keep coverage in force.
  • Deductibles — amounts the enrollee pays before the plan pays for most non-preventive services.
  • Copayments — fixed dollar amounts for specific services (for example, primary-care visits).
  • Coinsurance — percentage shares of allowed charges after the deductible.
  • Out-of-pocket maximums — annual caps on enrollee cost-sharing for covered, in-network services; once reached, the plan pays 100 percent of allowed amounts for the rest of the year.

Preventive services recommended by the U.S. Preventive Services Task Force and certain other services are often covered without cost-sharing when delivered in-network. Prescription-drug benefits typically use tiers (generic, preferred brand, non-preferred, specialty) with different cost-sharing. Out-of-network care is usually subject to higher cost-sharing and, in some plan types, to balance billing (subject to federal and state surprise-billing protections for emergency and certain other services).

High-deductible health plans paired with health savings accounts (HSAs) shift more first-dollar cost to the enrollee in exchange for lower premiums and tax-advantaged savings. Actuarial value (the share of allowed costs the plan is expected to pay for a standard population) is the formal metric that distinguishes metal tiers in the individual and small-group markets.

Networks, Medical Management, and Claims

Plans limit or price-differentiate care according to provider networks. HMOs and EPOs generally require in-network use except in emergencies; PPOs allow out-of-network use at higher cost-sharing. Prior authorization, concurrent review, step therapy, and referral requirements are widely used to manage utilization and cost. Claims may be denied for lack of medical necessity, non-covered services, coding or billing errors, or failure to follow plan procedures. Internal appeals and external review rights exist under federal and state law; success rates and timelines vary.

Pharmacy benefits are often administered by pharmacy benefit managers under contract with the insurer or employer. Formularies, prior authorization, and quantity limits are central tools. Hospital inpatient coverage is typically subject to benefit-period or episode rules, observation-status distinctions, and, for Medicare, specific deductible and coinsurance structures.

Regulatory Framework

  • Federal — ACA (individual and small-group standards, marketplaces, subsidies, essential health benefits, rating rules), ERISA (most employer plans), Medicare and Medicaid statutes and regulations, mental-health parity, surprise-billing protections, and nondiscrimination rules.
  • State — insurance licensing, solvency, form and rate review, network adequacy, consumer-protection rules, and, for Medicaid and CHIP, eligibility and benefit design within federal parameters.
  • Interaction — self-funded employer plans are largely outside state insurance regulation; Medicare Advantage and Medicaid managed-care plans operate under federal contracts with state overlays where applicable.

The result is a multi-jurisdictional system in which the same individual may move between regulated segments (employer, Marketplace, Medicare, Medicaid) over a lifetime, each with different rules and appeal pathways.

Major Transition and Coordination Points

  • Aging onto Medicare at 65 (or earlier via disability) and the choice among Original Medicare plus Medigap, Medicare Advantage, and employer retiree coverage.
  • Job change, loss of employer coverage, and the use of special enrollment periods or COBRA.
  • Income changes that affect Marketplace subsidy eligibility or Medicaid/CHIP eligibility.
  • Dual eligibility (Medicare + Medicaid) and the assignment of primary and secondary payment.
  • Coordination with workers’ compensation, auto no-fault, and liability insurance under Medicare secondary-payer and similar rules.
  • Continuous coverage gaps that trigger waiting periods, late-enrollment penalties (Medicare), or loss of guaranteed-issue protections in limited contexts.

Practical Considerations

For individuals and families
Identify the coverage channel for which you are eligible (employer, Marketplace, Medicare, Medicaid/CHIP). Compare plans on total expected cost (premium plus projected cost-sharing), network fit for usual and anticipated providers, formulary coverage for ongoing medications, and out-of-pocket maximum. Observe open-enrollment and special-enrollment deadlines. Keep documentation of qualifying events, income, and medical necessity determinations for appeals.

For employers
Comply with applicable ACA employer-responsibility and reporting rules, ERISA fiduciary and disclosure requirements, and state laws that apply to fully insured plans. Align plan design with workforce demographics and with Medicare secondary-payer obligations when covering active workers entitled to Medicare.

For advisors and case workers
Map the client across potential programs; watch for cliffs (subsidy and Medicaid income thresholds), waiting periods, and secondary-payer issues; document communications and deadlines for appeals.

Summary

Health Insurance in the United States is a plural system of employer plans, individual and Marketplace policies, Medicare, Medicaid, CHIP, and specialized public programs. Coverage is not automatic; it depends on age, income, employment, disability status, and timely enrollment. Recent data show employer coverage remaining the dominant source for the non-elderly, full-year uninsured rates near 8%, rising employer and Marketplace cost-sharing after the expiration of enhanced ACA premium tax credits, and continued importance of Medicare and Medicaid for seniors, people with disabilities, and low-income populations. Understanding which channel applies, how cost-sharing and networks work, and when transitions occur is essential to maintaining continuous and adequate protection.

Related topics on this site include Medicare Coverage, Medicaid Insurance, Children’s Health Insurance, Federal Employees Health Benefits, Hospital Insurance in the U.S., and National Insurance in the U.S. For eligibility determinations and current parameters, consult the administering agencies—CMS, state Medicaid and marketplace agencies, the Social Security Administration, and plan administrators—and primary data sources (Census Bureau, KFF Employer Health Benefits Survey, CMS Marketplace reports), because statutes, regulations, subsidy rules, and published statistics change.

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