Purpose: Although increased participation in physical activity by older adults is a major public health goal, little is known about the supply and use of physical activity programs in the United States. Design and Methods: Seven academic centers in diverse geographic areas surveyed physical activity programs for older adults. Five sites conducted surveys by mail with telephone follow-up, and two administered surveys primarily by telephone. Reported program attendance rates were compared with local census data to assess unmet needs. Results: Of the 2,110 targeted facilities, 77% responded. Aerobic programs were offered by 73%, flexibility by 47%, and strength training by 26%. Commercial gyms or YMCAs, senior centers, park or recreation centers, and senior-housing facilities offered 90% of available programs. The 2000 Census enumerated 1,123,401 total older adults across the seven sites. Facilities reported 69,634 individuals as current weekly program participants, equaling 6% of the sites' total older-adult population. This percentage varied from 3% in Pittsburgh to 28% in Colorado. Implications: Based on conservative estimates of demand, the number of physical activity programs would have to increase substantially (by 78%) to meet the needs of older adults. The data also indicate the need to develop more strength-training programs and to engage a higher percentage of older adults in these programs. There is a clear need to stimulate demand for programs through health promotion.