Historically, health insurance has been regulated by the states, consistent with the McCarran-Ferguson Act. Details for what health insurance could be sold were up to the states, with a variety of laws and regulations. Model acts and regulations promulgated by the National Association of Insurance Commissioners (NAIC) provide some degree of uniformity state to state. These models do not have the force of law and have no effect unless they are adopted by a state. They are, however, used as guides by most states, and some states adopt them with little or no change.

Through the 1990s, managed care insurance schemes including health maintenance organizations (HMO), preferred provider organizations, or point of service plans grew from about 25% US employees with employer-sponsored coverage to the vast majority.[69] With managed care, insurers use various techniques to address costs and improve quality, including negotiation of prices ("in-network" providers), utilization management, and requirements for quality assurance such as being accredited by accreditation schemes such as the Joint Commission and the American Accreditation Healthcare Commission.[70]

Persistent lack of insurance among many working Americans continued to create pressure for a comprehensive national health insurance system. In the early 1970s, there was fierce debate between two alternative models for universal coverage. Senator Ted Kennedy proposed a universal single-payer system, while President Nixon countered with his own proposal based on mandates and incentives for employers to provide coverage while expanding publicly run coverage for low-wage workers and the unemployed. Compromise was never reached, and Nixon's resignation and a series of economic problems later in the decade diverted Congress's attention away from health reform.

While politically difficult, some politicians and observers have argued for a single-payer system.[30] A bill, the United States National Health Care Act, was first proposed by Representative John Conyers in 2003[31] and has been perennially proposed since, including during the debate on the public option and the Patient Protection and Affordable Care Act.[32] President Obama has come out against a single-payer reform at this time, stating in the joint session of Congress that "it makes more sense to build on what works and fix what doesn't, rather than try to build an entirely new system from scratch."[33] Obama had previously expressed that he is a proponent of a single payer universal health care program during an AFL-CIO conference in 2003.[34]

-also referred to as the Allowed Amount, Approved Charge or Maximum Allowable. See also, Usual, Customary and Reasonable Charge. This is the dollar amount typically considered payment-in-full by an insurance company and an associated network of healthcare providers. The Allowable Charge is typically a discounted rate rather than the actual charge. It may be helpful to consider an example: You have just visited your doctor for an earache. The total charge for the visit comes to $100. If the doctor is a member of your health insurance company's network of providers, he or she may be required to accept $80 as payment in full for the visit - this is the Allowable Charge. Your health insurance company will pay all or a portion of the remaining $80, minus any co-payment or deductible that you may owe. The remaining $20 is considered provider write-off. You cannot be billed for this provider write-off. If, however, the doctor you visit is not a network provider then you may be held responsible for everything that your health insurance company will not pay, up to the full charge of $100.
Since people who lack health insurance are unable to obtain timely medical care, they have a 40% higher risk of death in any given year than those with health insurance, according to a study published in the American Journal of Public Health. The study estimated that in 2005 in the United States, there were 45,000 deaths associated with lack of health insurance.[14] A 2008 systematic review found consistent evidence that health insurance increased utilization of services and improved health.[15]

Public insurance cover increased from 2000–2010 in part because of an aging population and an economic downturn in the latter part of the decade. Funding for Medicaid and CHIP expanded significantly under the 2010 health reform bill.[9] The proportion of individuals covered by Medicaid increased from 10.5% in 2000 to 14.5% in 2010 and 20% in 2015. The proportion covered by Medicare increased from 13.5% in 2000 to 15.9% in 2010, then decreased to 14% in 2015.[3][10]