A health maintenance organization (HMO) is a type of managed care organization (MCO) that provides a form of health care coverage that is fulfilled through hospitals, doctors, and other providers with which the HMO has a contract. The Health Maintenance Organization Act of 1973 required employers with 25 or more employees to offer federally certified HMO options.[94] Unlike traditional indemnity insurance, an HMO covers only care rendered by those doctors and other professionals who have agreed to treat patients in accordance with the HMO's guidelines and restrictions in exchange for a steady stream of customers. Benefits are provided through a network of providers. Providers may be employees of the HMO ("staff model"), employees of a provider group that has contracted with the HMO ("group model"), or members of an independent practice association ("IPA model"). HMOs may also use a combination of these approaches ("network model").[19][95]
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.[65] The predecessors of today's Health Maintenance Organizations (HMOs) originated beginning in 1929, through the 1930s and on during World War II.[67][68]

In the late 1990s federal legislation had been proposed to "create federally-recognized Association Health Plans which was then "referred to in some bills as 'Small Business Health Plans.'[79] The National Association of Insurance Commissioners (NAIC), which is the "standard-setting and regulatory of chief insurance regulators from all states, the District of Columbia and territories, cautioned against implementing AHPs citing "plan failures like we saw The Multiple Employer Welfare Arrangements (MEWAs) in the 1990s."[80] "[S]mall businesses in California such as dairy farmers, car dealers, and accountants created AHPs "to buy health insurance on the premise that a bigger pool of enrollees would get them a better deal."[81] A November 2017 article in the Los Angeles Times described how there were only 4 remaining AHPs in California. Many of the AHPs filed for bankruptcy, "sometimes in the wake of fraud." State legislators were forced to pass "sweeping changes in the 1990s" that almost made AHPs extinct.[81]

Medicaid was instituted for the very poor in 1965. Since enrollees must pass a means test, Medicaid is a social welfare or social protection program rather than a social insurance program. Despite its establishment, the percentage of US residents who lack any form of health insurance has increased since 1994.[51] It has been reported that the number of physicians accepting Medicaid has decreased in recent years because of lower reimbursement rates.[52]
A number of alternatives to the public option were proposed in the Senate. Instead of creating a network of statewide public plans, Senator Olympia Snowe proposed a "trigger" in which a plan would be put into place at some point in the future in states that do not have more than a certain number of private insurance competitors. Senator Tom Carper has proposed an "opt-in" system in which state governments choose for themselves whether or not to institute a public plan. Senator Chuck Schumer has proposed an "opt-out" system in which state governments would initially be part of the network but could choose to avoid offering a public plan.[35]

A survey designed and conducted by Drs. Salomeh Keyhani and Alex Federman of Mount Sinai School of Medicine done over the summer of 2009 found that 73% of doctors supported a public option.[53] A survey reported by the New England Journal of Medicine in September, based on a random sample of 6,000 physicians from the American Medical Association, stated that "it seems clear that the majority of U.S. physicians support using both public and private insurance options to expand coverage."[54]
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.
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.[2]