Health insurance is a type of insurance whereby the insurer pays the medical costs of the insured if the insured becomes sick due to covered causes, or due to accidents. The insurer may be a private organization or a government agency. Market-based health care systems such as that in the United States rely primarily on private health insurance.
The concept of health insurance was proposed in 1694 by Hugh the Elder Chamberlen from the Peter Chamberlen family. In the late 19th century, early health insurance was actually disability insurance, in the sense that it covered only the cost of emergency care for injuries that could lead to a disability[citation needed]. This payment model continued until the start of the 21st century in some jurisdictions (like California), where all laws regulating health insurance actually referred to disability insurance. Patients were expected to pay all other health care costs out of their own pockets, under what is known as the fee-for-service business model. During the middle to late 20th century, traditional disability insurance evolved into modern health insurance programs. Today, most comprehensive private health insurance programs cover the cost of routine, preventive, and emergency health care procedures, and also most prescription drugs, but this was not always the case.