The Australian government announced in May 2008 that it proposes to increase the thresholds, to $100,000 for singles and $150,000 for families. These changes require legislative approval. A bill to change the law has been introduced but was not passed by the Senate.[12] An amended version was passed on 16 October 2008. There have been criticisms that the changes will cause many people to drop their private health insurance, causing a further burden on the public hospital system, and a rise in premiums for those who stay with the private system. Other commentators believe the effect will be minimal.[13]
Marcia Angell, M. D., Senior Lecturer in the Department of Social Medicine at Harvard Medical School and former Editor-in-Chief of the New England Journal of Medicine, believes that the result of a public option would be more "under-55's" opting to pay the fine rather than purchase insurance under a public option scenario, instead advocating lowering the Medicare age to 55.[40]
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]
Prior to the Patient Protection and Affordable Care Act, effective from 2014, about 34 states offered guaranteed-issuance risk pools, which enabled individuals who are medically uninsurable through private health insurance to purchase a state-sponsored health insurance plan, usually at higher cost, with high deductibles and possibly lifetime maximums.[30] Plans varied greatly from state to state, both in their costs and benefits to consumers and in their methods of funding and operations. The first such plan was implemented In 1976.[30]

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.[78]

The share of Americans without health insurance has been cut in half since 2013. Many of the reforms instituted by the Affordable Care Act of 2010 were designed to extend health care coverage to those without it; however, high cost growth continues unabated.[3] National health expenditures are projected to grow 4.7% per person per year from 2016 to 2025. Public healthcare spending was 29% of federal mandated spending in 1990 and 35% of it in 2000. It is also projected to be roughly half in 2025.[4]