Objective. To quantify the incidence of symptomatic hand, hip, and knee osteoarthritis (OA) among members of the Fallen Community Health Plan, a health maintenance organization located in central Massachusetts, Methods. Incident OA was defined as the first evidence of OA by radiography (grade greater than or equal to 2 on the Kellgren-Lawrence scale of 0-4) pins joint symptoms at the time the radiograph was obtained or up to 1 year before the radiograph was obtained, Results. The age- and sex-standardized incidence rate for hand OA was 100/100,000 person-years (95% confidence interval [95% CI] 86,115), for hip OA 88/100,000 person-years (95% CI75,101), and for knee OA 240/100,000 person-years (95% CI 218,262), The incidence of hand, hip, and knee OA increased with age, and women had higher rates than men, especially after age 50, A leveling off or decline occurred for both groups around the age of 80, Conclusion, In a large study of symptomatic OA we observed incidence rates that increased with age, In women ages 70-89, the incidence of knee OA approached 1% per year.