The present study expands upon the data available in the manual of the Repeatable Battery for the Assessment of Neuropsychological Status [Randolph, C. (1998). Repeatable battery for the assessment of neuropsychological status manual. San Antonio, TX: The Psychological Corporation], by providing base rate data on Index discrepancies that are organized by general level of ability and include both age and education corrections. The data presented are based on the performances of a sample of 718 community dwelling older adults. These findings offer the possibility of increased sensitivity at detecting clinically significant differences that might not be identified when relying on base rate data from a greater age range. Similarly, these data highlight the mediating effects of the global level of cognitive functioning on discrepancy scores.