Health insurance primarily protects individuals from the prohibitively high costs of surgical procedures, inpatient hospital care, and emergency attention. Though health insurance itself can become costly for a family, it is only a small fraction of the potential costs associated with unforeseen illnesses and emergencies (for example, the diagnosis and treatment of cancer or a heart attack).

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.

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.[116] The US Department of Justice has recognized this percentage of market control as conferring substantial monopsony power in the relations between insurer and physicians.[117]
The Commonwealth Fund, in its annual survey, "Mirror, Mirror on the Wall", compares the performance of the health care systems in Australia, New Zealand, the United Kingdom, Germany, Canada and the U.S. Its 2007 study found that, although the U.S. system is the most expensive, it consistently under-performs compared to the other countries.[6] One difference between the U.S. and the other countries in the study is that the U.S. is the only country without universal health insurance coverage.
Health insurance companies are not actually providing traditional insurance, which involves the pooling of risk, because the vast majority of purchasers actually do face the harms that they are "insuring" against. Instead, as Edward Beiser and Jacob Appel have separately argued, health insurers are better thought of as low-risk money managers who pocket the interest on what are really long-term healthcare savings accounts.[131][132]
You may be able to get extra help to pay for your prescription drug premiums and costs. To see if you qualify for getting extra help, call: 1-800-MEDICARE (800-633-4227). TTY or TDD users should call 877-486-2048, 24 hours a day/7 days a week; The Social Security Office at 800-772-1213 between 7 a.m. and 7 p.m., Monday through Friday. TTY or TDD users should call, 800-325-0778; or Your State Medical Assistance (Medicaid) Office.