However, with the Patient Protection and Affordable Care Act, effective since 2014, federal laws have created some uniformity in partnership with the existing state-based system. Insurers are prohibited from discriminating against or charging higher rates for individuals based on pre-existing medical conditions and must offer a standard set of coverage.
Employer-sponsored health insurance plans dramatically expanded as a direct result of wage controls imposed by the federal government during World War II. The labor market was tight because of the increased demand for goods and decreased supply of workers during the war. Federally imposed wage and price controls prohibited manufacturers and other employers from raising wages enough to attract workers. When the War Labor Board declared that fringe benefits, such as sick leave and health insurance, did not count as wages for the purpose of wage controls, employers responded with significantly increased offers of fringe benefits, especially health care coverage, to attract workers.
Medicare Supplement policies are designed to cover expenses not covered (or only partially covered) by the "original Medicare" (Parts A & B) fee-for-service benefits. They are only available to individuals enrolled in Medicare Parts A & B. Medigap plans may be purchased on a guaranteed issue basis (no health questions asked) during a six-month open enrollment period when an individual first becomes eligible for Medicare. The benefits offered by Medigap plans are standardized.
Employers and employees may have some choice in the details of plans, including health savings accounts, deductible, and coinsurance. As of 2015, a trend has emerged for employers to offer high-deductible plans, called consumer-driven healthcare plans which place more costs on employees; some employers will offer multiple plans to their employees.
Foreseeing a long and costly political battle, many labor unions chose to campaign for employer-sponsored coverage, which they saw as a less desirable but more achievable goal, and as coverage expanded the national insurance system lost political momentum and ultimately failed to pass. Using health care and other fringe benefits to attract the best employees, private sector, white-collar employers nationwide expanded the U.S. health care system. Public sector employers followed suit in an effort to compete. Between 1940 and 1960, the total number of people enrolled in health insurance plans grew seven-fold, from 20,662,000 to 142,334,000, and by 1958, 75% of Americans had some form of health coverage.
In addition to medical expense insurance, "health insurance" may also refer to insurance covering disability or long-term nursing or custodial care needs. Different health insurance provides different levels of financial protection and the scope of coverage can vary widely, with more than 40% of insured individuals reporting that their plans do not adequately meet their needs as of 2007.