The blurring of distinctions between the different types of health care coverage can be seen in the history of the industry's trade associations. The two primary HMO trade associations were the Group Health Association of America and the American Managed Care and Review Association. After merging, they were known as American Association of Health Plans (AAHP). The primary trade association for commercial health insurers was the Health Insurance Association of America (HIAA). These two have now merged, and are known as America's Health Insurance Plans (AHIP).
Network-based plans may be either closed or open. With a closed network, enrollees' expenses are generally only covered when they go to network providers. Only limited services are covered outside the network—typically only emergency and out-of-area care. Most traditional HMOs were closed network plans. Open network plans provide some coverage when an enrollee uses non-network provider, generally at a lower benefit level to encourage the use of network providers. Most preferred provider organization plans are open-network (those that are not are often described as exclusive provider organizations, or EPOs), as are point of service (POS) plans.

Private health care has continued parallel to the NHS, paid for largely by private insurance, but it is used by less than 8% of the population, and generally as a top-up to NHS services. There are many treatments that the private sector does not provide. For example, health insurance on pregnancy is generally not covered or covered with restricting clauses. Typical exclusions for Bupa schemes (and many other insurers) include:
^ Leichter, Howard M. (1979). A comparative approach to policy analysis: health care policy in four nations. Cambridge: Cambridge University Press. p. 121. ISBN 978-0-521-22648-6. The Sickness Insurance Law (1883). Eligibility. The Sickness Insurance Law came into effect in December 1884. It provided for compulsory participation by all industrial wage earners (i.e., manual laborers) in factories, ironworks, mines, shipbuilding yards, and similar workplaces.
In 2003, according to the Heartland Institute's Merrill Matthews, association group health insurance plans offered affordable health insurance to "some 6 million Americans." Matthews responded to the criticism that said that some associations work too closely with their insurance providers. He said, "You would expect the head of AARP to have a good working relationship with the CEO of Prudential, which sells policies to AARP's seniors."[83]
Scheduled health insurance plans are an expanded form of Hospital Indemnity plans. In recent years, these plans have taken the name mini-med plans or association plans. These plans may provide benefits for hospitalization, surgical, and physician services. However, they are not meant to replace a traditional comprehensive health insurance plan. Scheduled health insurance plans are more of a basic policy providing access to day-to-day health care such as going to the doctor or getting a prescription drug, but these benefits will be limited and are not meant to be effective for catastrophic events. Payments are based upon the plan's "schedule of benefits" and are usually paid directly to the service provider. These plans cost much less than comprehensive health insurance. Annual benefit maximums for a typical scheduled health insurance plan may range from $1,000 to $25,000.

According to some experts, such as Uwe Reinhardt,[120] Sherry Glied, Megan Laugensen,[121] Michael Porter, and Elizabeth Teisberg,[122] this pricing system is highly inefficient and is a major cause of rising health care costs. Health care costs in the United States vary enormously between plans and geographical regions, even when input costs are fairly similar, and rise very quickly. Health care costs have risen faster than economic growth at least since the 1970s. Public health insurance programs typically have more bargaining power as a result of their greater size and typically pay less for medical services than private plans, leading to slower cost growth, but the overall trend in health care prices have led public programs' costs to grow at a rapid pace as well.

Coinsurance: Instead of, or in addition to, paying a fixed amount up front (a co-payment), the co-insurance is a percentage of the total cost that insured person may also pay. For example, the member might have to pay 20% of the cost of a surgery over and above a co-payment, while the insurance company pays the other 80%. If there is an upper limit on coinsurance, the policy-holder could end up owing very little, or a great deal, depending on the actual costs of the services they obtain.

In addition to medical expense insurance, "health insurance" may also refer to insurance covering disability or long-term nursing or custodial care needs. Different health insurance provides different levels of financial protection and the scope of coverage can vary widely, with more than 40% of insured individuals reporting that their plans do not adequately meet their needs as of 2007.[2]