main article: children's health insurance program 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. military health benefits health benefits are provided to active duty service members, retired service members and their dependents by the department of defense military health system (mhs). the mhs consists of a direct care network of military treatment facilities and a purchased care network known as tricare. additionally, veterans may also be eligible for benefits through the veterans health administration. indian health service the indian health service (ihs) provides medical assistance to eligible american indians at ihs facilities, and helps pay the cost of some services provided by non-ihs health care providers. private health care coverage 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. 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. the us has a joint federal and state system for regulating insurance, with the federal government ceding primary responsibility to the states under the mccarran-ferguson act. states regulate the content of health insurance policies and often require coverage of specific types of medical services or health care providers. state mandates generally do not apply to the health plans offered by large employers, because of the preemption clause of the employee retirement income security act. symbolism of health insurance as of 2018, there were 953 health insurance companies in the united states, although the top 10 account for about 53% of revenue and the top 100 account for 95% of revenue.: 70 employer sponsored employer-sponsored health insurance is paid for by businesses on behalf of their employees as part of an employee benefit package. most private (non-government) health coverage in the us is employment-based. nearly all large employers in america offer group health insurance to their employees. the typical large-employer ppo plan is typically more generous than either medicare or the federal employees health benefits program standard option. the employer typically makes a substantial contribution towards the cost of coverage. typically, employers pay about 85% of the insurance premium for their employees, and about 75% of the premium for their employees' dependents. the employee pays the remaining fraction of the premium, usually with pre-tax/tax-exempt earnings. these percentages have been stable since 1999. health benefits provided by employers are also tax-favored: employee contributions can be made on a pre-tax basis if the employer offers the benefits through a section 125 cafeteria plan. workers who receive employer-sponsored health insurance tend to be paid less in cash wages than they would be without the benefit, because of the cost of insurance premiums to the employer and the value of the benefit to the worker. the value to workers is generally greater than the wage reduction because of economies of scale, a reduction in adverse selection pressures on the insurance pool (premiums are lower when all employees participate rather than just the sickest), and reduced income taxes. disadvantages to workers include disruptions related to changing jobs, the regressive tax effect (high-income workers benefit far more from the tax exemption for premiums than low-income workers), and increased spending on healthcare. costs for employer-paid health insurance are rising rapidly: between 2001 and 2007, premiums for family coverage have increased 78%, while wages have risen 19% and inflation has risen 17%, according to a 2007 study by the kaiser family foundation. employer costs have risen noticeably per hour worked, and vary significantly. in particular, average employer costs for health benefits vary by firm size and occupation. the cost per hour of health benefits is generally higher for workers in higher-wage occupations, but represent a smaller percentage of payroll. the percentage of total compensation devoted to health benefits has been rising since the 1960s. average premiums, including both the employer and employee portions, were $4,704 for single coverage and $12,680 for family coverage in 2008. however, in a 2007 analysis, the employee benefit research institute concluded that the availability of employment-based health benefits for active workers in the us is stable. the "take-up rate," or percentage of eligible workers participating in employer-sponsored plans, has fallen somewhat, but not sharply. ebri interviewed employers for the study, and found that others might follow if a major employer discontinued health benefits. effective by january 1, 2014, the patient protection and affordable care act will impose a $2000 per employee tax penalty on employers with over 50 employees who do not offer health insurance to their full-time workers. (in 2008, over 95% of employers with at least 50 employees offered health insurance.) on the other hand, public policy changes could also result in a reduction in employer support for employment-based health benefits. although much more likely to offer retiree health benefits than small firms, the percentage of large firms offering these benefits fell from 66% in 1988 to 34% in 2002. according to jacob hacker, the development of employer-based health insurance during world war ii has contributed to the difficulty in the united states of enacting reforms to the health insurance system. small employer group coverage according to a 2007 study, about 59% of employers at small firms (3–199 workers) in the us provide employee health insurance. the percentage of small firms offering coverage has been dropping steadily since 1999. the study notes that cost remains the main reason cited by small firms who do not offer health benefits. small firms that are new are less likely to offer coverage than ones that have been in existence for a number of years. for example, using 2005 data for firms with fewer than 10 employees, 43% of those that had been in existence at least 20 years offered coverage, but only 24% of those that had been in existence less than 5 years did. the volatility of offer rates from year to year also appears to be higher for newer small businesses. the types of coverage available to small employers are similar to those offered by large firms, but small businesses do not have the same options for financing their benefit plans. in particular, self-funded health care (whereby an employer provides health or disability benefits to employees with its own funds rather than contracting an insurance company) is not a practical option for most small employers. a rand corporation study published in april 2008 found that the cost of health care coverage places a greater burden on small firms, as a percentage of payroll, than on larger firms. a study published by the american enterprise institute in august 2008 examined the effect of state benefit mandates on self-employed individuals, and found that "the larger the number of mandates in a state, the lower the probability that a self-employed person will be a significant employment generator." beneficiary cost sharing is, on average, higher among small firms than large firms. when small group plans are medically underwritten, employees are asked to provide health information about themselves and their covered family members when they apply for coverage. when determining rates, insurance companies use the medical information on these applications. sometimes they will request additional information from an applicant's physician or ask the applicants for clarification. states regulate small group premium rates, typically by placing limits on the premium variation allowable between groups (rate bands). insurers price to recover their costs over their entire book of small group business while abiding by state rating rules. over time, the effect of initial underwriting "wears off" as the cost of a group regresses towards the mean. recent claim experience—whether better or worse than average—is a strong predictor of future costs in the near term. but the average health status of a particular small employer group tends to regress over time towards that of an average group. the process used to price small group coverage changes when a state enacts small group reform laws. insurance brokers play a significant role in helping small employers find health insurance, particularly in more competitive markets. average small group commissions range from 2 percent to 8 percent of premiums. brokers provide services beyond insurance sales, such as assisting with employee enrollment and helping to resolve benefits issues. college-sponsored health insurance for students many colleges, universities, graduate schools, professional schools and trade schools offer a school-sponsored health insurance plan. many schools require that you enroll in the school-sponsored plan unless you are able to show that you have comparable coverage from another source. effective group health plan years beginning after september 23, 2010, if an employer-sponsored health plan allows employees' children to enroll in coverage, then the health plan must allow employees' adult children to enroll as well as long as the adult child is not yet age 26. some group health insurance plans may also require that the adult child not be eligible for other group health insurance coverage, but only before 2014. this extension of coverage will help cover one in three young adults, according to white house documents. federal employees health benefit plan (fehbp) 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. cobra coverage 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. association health plan (ahp) 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.' 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." "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." 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. according to a 2000 congressional budget office (cbo) report, congress passed legislation creating "two new vehicles association health plans (ahps) and healthmarts, to facilitate the sale of health insurance coverage to employees of small firms" in response to concerns about the "large and growing number of uninsured people in the united states." in march 2017, the u.s. house of representatives passed the small business health fairness act (h.r. 1101), which established "requirements for creating a federally-certified ahp, including for certification itself, sponsors and boards of trustees, participation and coverage, nondiscrimination, contribution rates, and voluntary termination." ahps would be "exempt from most state regulation and oversight,