National longitudinal study of cognition, focused on the age-related changes in cognition across cohorts and on the impact of cognition on key health and economic outcomes. The aim of the CogUSA Study was to evaluate the effectiveness of a variety of tests in assessing cognitive skills on a sample mirroring the Health and Retirement Survey. Data were derived in 3 waves, with each wave utilizing a variety of measures. In Waves 1 and 3, these measures included an adaptive number series test. The Woodcock-Johnson (WJ-III) number series test and the Wechsler Abbreviated Scale of Intelligence (WASI) were used in Wave 2. Waves 1 and 3 were conducted as telephone interviews, while Wave 2 was conducted as an in-person interview. This collection includes indicators of cognitive abilities and functioning as well as a variety of demographic, health, and economic variables. Dataset 1 presents participant demographic information, and Dataset 2 presents scores calculated for the cognitive tests administered to the respondents in each of the 3 waves.