The Age Discrimination in Employment Act of 1967 (ADEA) prohibits discrimination against persons aged 40 to 65; the ADEA Amendments of 1978 restrict mandatory retirement. Age 65 has been widely regarded as a customary age for retirement, given widespread eligibility for retirement benefits at that age. Substantial numbers of older workers leave the labor force. As more people continue to enjoy good health and are able to remain active through their 60s and beyond, the concept of what constitutes old age is shifting. Factors that affect the retirement decision include retirement benefits, age discrimination, mandatory retirement, and health. Findings of a study of mandatory retirement policies show that employees continued to retire at relatively early ages; competition between older workers and youth, minorities, and women was minimal; and elimination of mandatory retirement will induce older workers to remain in the labor force. The 1978 ADEA Amendments permits mandatory retirement of executives and tenured faculty members at institutions of higher education between ages 65 and 69. The provision for the second group has since expired. (Recommendations are made for elimination of the mandatory retirement age, increased information dissemination, and encouragement of implementation of nondiscriminatory older worker employment policies.) (YLB)