As the population covered by Medicare grows, its costs are projected to rise from slightly over 3 percent of GDP to over 6 percent, contributing substantially to the federal budget deficit.[47] In 2011, Medicare was the primary payer for an estimated 15.3 million inpatient stays, representing 47.2 percent ($182.7 billion) of total aggregate inpatient hospital costs in the United States.[12] The Affordable Care Act took some steps to reduce Medicare spending, and various other proposals are circulating to reduce it further.

The Consolidated Omnibus Budget Reconciliation Act of 1985 (COBRA) enables certain individuals with employer-sponsored coverage to extend their coverage if certain "qualifying events" would otherwise cause them to lose it. Employers may require COBRA-qualified individuals to pay the full cost of coverage, and coverage cannot be extended indefinitely. COBRA only applies to firms with 20 or more employees, although some states also have "mini-COBRA" laws that apply to small employers.
Hospital and medical expense policies were introduced during the first half of the 20th century. During the 1920s, individual hospitals began offering services to individuals on a pre-paid basis, eventually leading to the development of Blue Cross organizations in the 1930s.[19] The first employer-sponsored hospitalization plan was created by teachers in Dallas, Texas in 1929.[20] Because the plan only covered members' expenses at a single hospital, it is also the forerunner of today's health maintenance organizations (HMOs).[20][21][22]
Funding from the equalization pool is distributed to insurance companies for each person they insure under the required policy. However, high-risk individuals get more from the pool, and low-income persons and children under 18 have their insurance paid for entirely. Because of this, insurance companies no longer find insuring high risk individuals an unappealing proposition, avoiding the potential problem of adverse selection.
The Commonwealth Fund completed its thirteenth annual health policy survey in 2010.[8] A study of the survey "found significant differences in access, cost burdens, and problems with health insurance that are associated with insurance design".[8] Of the countries surveyed, the results indicated that people in the United States had more out-of-pocket expenses, more disputes with insurance companies than other countries, and more insurance payments denied; paperwork was also higher although Germany had similarly high levels of paperwork.[8]
Insurance companies are not allowed to have co-payments, caps, or deductibles, or to deny coverage to any person applying for a policy, or to charge anything other than their nationally set and published standard premiums. Therefore, every person buying insurance will pay the same price as everyone else buying the same policy, and every person will get at least the minimum level of coverage.
The US has a joint federal and state system for regulating insurance, with the federal government ceding primary responsibility to the states under the McCarran-Ferguson Act. States regulate the content of health insurance policies and often require coverage of specific types of medical services or health care providers.[54][55] State mandates generally do not apply to the health plans offered by large employers, because of the preemption clause of the Employee Retirement Income Security Act.
Carrin, Guy; James, Chris (January 2005). "Social health insurance: Key factors affecting the transition towards universal coverage" (PDF). International Social Security Review. 58 (1): 45–64. doi:10.1111/j.1468-246x.2005.00209.x. Retrieved 10 March 2013. Initially the health insurance law of 1883 covered blue-collar workers in selected industries, craftspeople and other selected professionals.6 It is estimated that this law brought health insurance coverage up from 5 to 10 per cent of the total population.
Health insurance in the United States is any program that helps pay for medical expenses, whether through privately purchased insurance, social insurance, or a social welfare program funded by the government.[1] Synonyms for this usage include "health coverage", "health care coverage", and "health benefits". In a more technical sense, the term "health insurance" is used to describe any form of insurance providing protection against the costs of medical services. This usage includes private insurance and social insurance programs such as Medicare, which pools resources and spreads the financial risk associated with major medical expenses across the entire population to protect everyone, as well as social welfare programs like Medicaid and the Children's Health Insurance Program, which both provide assistance to people who cannot afford health coverage.