Clinicians and researchers who use neuropsychological tests to track functioning over time are in need of a method to correct for the effects of practice. Drawing from a large database of healthy, male subjects, we present data that can be used to calculate predicted retest scores for eight widely used neuropsychological instruments either via simple regression or reliable change index (RCI) methods. These methods are useful for individuals assessed across a wide time interval, 4-24 months. Limitations are discussed regarding the applicability of the data. Those with a need to factor out the effects of practice, test-retest reliability and other statistical confounds will find the information within this article useful.