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.
Private Health Insurance Rebate: The government subsidises the premiums for all private health insurance cover, including hospital and ancillary (extras), by 10%, 20% or 30%, depending on age. The Rudd Government announced in May 2009 that as of July 2010, the Rebate would become means-tested, and offered on a sliding scale. While this move (which would have required legislation) was defeated in the Senate at the time, in early 2011 the Gillard Government announced plans to reintroduce the legislation after the Opposition loses the balance of power in the Senate. The ALP and Greens have long been against the rebate, referring to it as "middle-class welfare".
Private health insurance may be purchased on a group basis (e.g., by a firm to cover its employees) or purchased by individual consumers. Most Americans with private health insurance receive it through an employer-sponsored program. According to the United States Census Bureau, some 60% of Americans are covered through an employer, while about 9% purchase health insurance directly. Private insurance was billed for 12.2 million inpatient hospital stays in 2011, incurring approximately 29% ($112.5 billion) of the total aggregate inpatient hospital costs in the United States.
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.