In general, the amount the employer must include is the amount by which the fair market value of the benefits is more than the sum of what the employee paid for it plus any amount that the law excludes. There are other special rules that employers and employees may use to value certain fringe benefits. See Publication 15-B, Employers' Tax Guide to Fringe Benefits, for more information.

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 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.
Michael F. Cannon, a senior fellow of the libertarian CATO Institute, has argued that the federal government can hide inefficiencies in its administration and draw away consumers from private insurance even if the government offers an inferior product. A study by the Congressional Budget Office found that profits accounted for only about 4 or 5 percent of private health insurance premiums, and Cannon argued that the lack of a profit motive reduces incentives to eliminate wasteful administrative costs.[38]
The purpose behind the public option was to make more affordable health insurance for uninsured citizens who are either unable to afford the rates of or are rejected by private health insurers. Supporters argued that a government insurance company could successfully lower its rates by using greater leverage than private industry when negotiating with hospitals and doctors,[18] as well as paying the employees of the public option insurance company salaries as opposed to paying based on individual medical procedures.[19]
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]

Private health insurance may be purchased on a group basis (e.g., by a firm to cover its employees) or purchased by individual consumers. Most Americans with private health insurance receive it through an employer-sponsored program. According to the United States Census Bureau, some 60% of Americans are covered through an employer, while about 9% purchase health insurance directly.[53] Private insurance was billed for 12.2 million inpatient hospital stays in 2011, incurring approximately 29% ($112.5 billion) of the total aggregate inpatient hospital costs in the United States.[12]
In addition to such public plans as Medicare and Medicaid, the federal government also sponsors a health benefit plan for federal employees—the Federal Employees Health Benefits Program (FEHBP). FEHBP provides health benefits to full-time civilian employees. Active-duty service members, retired service members and their dependents are covered through the Department of Defense Military Health System (MHS). FEHBP is managed by the federal Office of Personnel Management.
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]