Private insurers offer a variety of supplemental coverages in both the group and individual markets. These are not designed to provide the primary source of medical or disability protection for an individual, but can assist with unexpected expenses and provide additional peace of mind for insureds. Supplemental coverages include Medicare supplement insurance, hospital indemnity insurance, dental insurance, vision insurance, accidental death and dismemberment insurance and specified disease insurance.
Supporters of a public plan, such as Washington Post columnist E. J. Dionne, argue that many places in the United States have monopolies in which one company, or a small set of companies, control the local market for health insurance. Economist and New York Times columnist Paul Krugman also wrote that local insurance monopolies exist in many of the smaller states, accusing those who oppose the idea of a public insurance plan as defenders of local monopolies. He also argued that traditional ideas of beneficial market competition do not apply to the insurance industry given that insurers mainly compete by risk selection, claiming that "[t]he most successful companies are those that do the best job of denying coverage to those who need it most."
Early hospital and medical plans offered by insurance companies paid either a fixed amount for specific diseases or medical procedures (schedule benefits) or a percentage of the provider's fee. The relationship between the patient and the medical provider was not changed. The patient received medical care and was responsible for paying the provider. If the service was covered by the policy, the insurance company was responsible for reimbursing or indemnifying the patient based on the provisions of the insurance contract ("reimbursement benefits"). Health insurance plans that are not based on a network of contracted providers, or that base payments on a percentage of provider charges, are still described as indemnity or fee-for-service plans.
In the United States, Medicare is a federal social insurance program that provides health insurance to people over the age of 65, individuals who become totally and permanently disabled, end stage renal disease (ESRD) patients, and people with ALS. Recent research has found that the health trends of previously uninsured adults, especially those with chronic health problems, improves once they enter the Medicare program. Traditional Medicare requires considerable cost-sharing, but ninety percent of Medicare enrollees have some kind of supplemental insurance—either employer-sponsored or retiree coverage, Medicaid, or a private Medigap plan—that covers some or all of their cost-sharing. With supplemental insurance, Medicare ensures that its enrollees have predictable, affordable health care costs regardless of unforeseen illness or injury.
In July 2009, Save Flexible Spending Plans, a national grassroots advocacy organization, was formed to protect against the restricted use of FSAs in health care reform efforts, Save Flexible Spending Accounts is sponsored by the Employers Council on Flexible Compensation (ECFC), a non-profit organization "dedicated to the maintenance and expansion of the private employee benefits on a tax-advantaged basis". ECFC members include companies such as WageWorks Inc., a benefits provider based in San Mateo, California.
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.