Age-adjusted normative data are presented for persons over age 55 years on a common measure of category fluency. Further adjustment for education is also provided. These data were obtained as part of a series of projects known collectively as Mayo's Older Americans Normative Studies (MOANS). The normative information provided here should prove useful for characterizing performance on the individual measure of category fluency. In addition, these data should promote greater accuracy in comparing category fluency scores with performance on any other measures with MOANS norms, including tests of letter fluency. Limitations and unique features of MOANS normative data are also discussed.