Effects of additional test experience on longitudinal change in 5 cognitive abilities was examined in a sample of healthy adults ranging from 18 to 80 years of age. Participants receiving experience with parallel versions of the cognitive tests on the first occasion had more positive cognitive change an average of 2.5 years later than participants performing only a single version of the tests on the first occasion. Importantly, these test experience effects were similar in adults of different ages, which implies that retest contributions to cognitive change are comparable among healthy adults between 18 and 80 years of age.