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. 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").
Approximately 19 percent of Americans had coverage under Medicaid in 2016, and 14 percent had coverage under Medicare. These are government-run programs, as opposed to private coverage. However, the state and federal governments contract with private insurers to offer Medicaid managed care plans and Medicare Advantage plans, all of which are run by private insurers (in many cases, the same private insurers that offer employer-sponsored and individual market plans to the rest of the population).
A 2011 study found that there were 2.1 million hospital stays for uninsured patients, accounting for 4.4% ($17.1 billion) of total aggregate inpatient hospital costs in the United States. The costs of treating the uninsured must often be absorbed by providers as charity care, passed on to the insured via cost-shifting and higher health insurance premiums, or paid by taxpayers through higher taxes.
Disability income (DI) insurance pays benefits to individuals who become unable to work because of injury or illness. DI insurance replaces income lost while the policyholder is unable to work during a period of disability (in contrast to medical expense insurance, which pays for the cost of medical care). For most working age adults, the risk of disability is greater than the risk of premature death, and the resulting reduction in lifetime earnings can be significant. Private disability insurance is sold on both a group and an individual basis. Policies may be designed to cover long-term disabilities (LTD coverage) or short-term disabilities (STD coverage). Business owners can also purchase disability overhead insurance to cover the overhead expenses of their business while they are unable to work.
The US health insurance market is highly concentrated, as leading insurers have carried out over 400 mergers from the mid-1990s to the mid-2000s (decade). In 2000, the two largest health insurers (Aetna and UnitedHealth Group) had total membership of 32 million. By 2006 the top two insurers, WellPoint (now Anthem) and UnitedHealth, had total membership of 67 million. The two companies together had more than 36% of the national market for commercial health insurance. The AMA has said that it "has long been concerned about the impact of consolidated markets on patient care." A 2007 AMA study found that in 299 of the 313 markets surveyed, one health plan accounted for at least 30% of the combined health maintenance organization (HMO)/preferred provider organization (PPO) market. In 90% of markets, the largest insurer controls at least 30% of the market, and the largest insurer controls more than 50% of the market in 54% of metropolitan areas. The US Department of Justice has recognized this percentage of market control as conferring substantial monopsony power in the relations between insurer and physicians.
The Children's Health Insurance Program (CHIP) is a joint state/federal program to provide health insurance to children in families who earn too much money to qualify for Medicaid, yet cannot afford to buy private insurance. The statutory authority for CHIP is under title XXI of the Social Security Act. CHIP programs are run by the individual states according to requirements set by the federal Centers for Medicare and Medicaid Services, and may be structured as independent programs separate from Medicaid (separate child health programs), as expansions of their Medicaid programs (CHIP Medicaid expansion programs), or combine these approaches (CHIP combination programs). States receive enhanced federal funds for their CHIP programs at a rate above the regular Medicaid match.
An alternative proposal is to subsidize private, non-profit health insurance cooperatives to get them to become large and established enough to possibly provide cost savings Democratic politicians such as Howard Dean were critical of abandoning a public option in favor of co-ops, raising questions about the ability of the cooperatives to compete with existing private insurers. Paul Krugman also questioned the ability of cooperatives to compete.