The recent decline in the labor force participation rates of older Americans is well known and well documented. Dramatic changes in male participation rates occurred between 1968 and 1986. Declines were substantial as early as age 55 and as late as age 70. The trends for older women were much less dramatic. In 1988, nearly half of employed men and more than half of employed women aged 65 and over were working part time, voluntarily, compared to about 6 percent of men and 23 percent of women less than 65. Older workers were more likely to be self-employed than were members of any other age group. Determinants of the retirement decision included economic incentives, health, and labor market obstacles. Mandatory retirement has virtually been eliminated. Social security amendments will delay the age of eligibility for full retirement benefits to 67. These changes should work to increase the labor force participation of older workers, although recent research suggested that the impact will be modest. Little is known about how employer pension plans will change in response to social security rule changes. Surveys suggested that many older workers would like to retire gradually, although currently only a minority do. Policies that facilitate gradual retirement by making it less costly for firms to hire part-time workers and less costly for older workers to accept part-time employment should be considered. (A 73-item reference list is included in the document.) (CML)