Book excerpt: When the Medicare program was established in 1965, it was viewed as a form of financial protection for the elderly against catastrophic medical expenses, primarily those related to hospitalization for unexpected illnesses. The first expansions to the program increased the eligible population from the retired to the disabled and to persons receiving chronic renal dialysis. It was not until 1980 that an expansion of services beyond those required "for the diagnosis or treatment of illness or injury or to improve the functioning of a malformed body member" was included in Medicare. These services, known as preventive services, are intended either to prevent disease (by vaccination) or to detect disease (by diagnostic test) before the symptoms of illness appear. A Committee was formed "to conduct a study on the addition of coverage of routine thyroid screening using a thyroid stimulating hormone test as a preventive benefit provided to Medicare beneficiaries under Title XVIII of the Social Security Act for some or all Medicare beneficiaries."