Efforts to pass a national pool were unsuccessful for many years. With the Patient Protection and Affordable Care Act, it became easier for people with pre-existing conditions to afford regular insurance, since all insurers are fully prohibited from discriminating against or charging higher rates for any individuals based on pre-existing medical conditions.[31][32] Therefore, most of the state-based pools shut down.[33] As of 2017, some remain due to statutes which have not been updated, but they also may cover people with gaps in coverage such as undocumented immigrants[33] or Medicare-eligible individuals under the age of 65.[33]
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]
With the passing of the Affordable Care Act, or Obamacare, there is no longer a limit on how much your health insurance will pay.  Before Obamacare was law, health insurance policies had a lifetime maximum of $1 million, $2 million, or sometimes $5 million dollars. Someone with ongoing cancer surgeries and treatment could hit that $1 million mark easily, and then be left without health insurance unless they enrolled in an expensive, high risk insurance program. Today those barriers are gone, and individuals who need health insurance to treat chronic illnesses are able to get the care they need without worrying about hitting a maximum amount on their healthcare plan.

Bärnighausen, Till; Sauerborn, Rainer (May 2002). "One hundred and eighteen years of the German health insurance system: are there any lessons for middle- and low income countries?" (PDF). Social Science & Medicine. 54 (10): 1559–87. doi:10.1016/S0277-9536(01)00137-X. PMID 12061488. Retrieved 10 March 2013. As Germany has the world's oldest SHI [social health insurance] system, it naturally lends itself to historical analyses.
As of 2014, more than three-quarters of the country’s Medicaid enrollees were covered under private Medicaid managed care plans, and 31 percent of Medicare beneficiaries were enrolled in private Medicare Advantage plans in 2016. However, the funding for these plans still comes from the government (federal for Medicare Advantage, and a combination of state and federal funding for Medicaid managed care).

The average rates paid for health insurance plans are inversely related to the amount of coverage they provide, with Platinum plans being the most expensive and Bronze / Catastrophic plans being the cheapest. The following table shows the average rates a 21 year old would pay for individual health insurance based on plans in the different tiers. Older consumers would see their plans increase according to the age scale set by the federal guidelines.

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]