The NIH Toolbox for the Assessment of Neurological and Behavioral Function is a multidimensional set of brief royalty-free measures that researchers and clinicians can use to assess cognitive, sensory, motor and emotional function in people ages 3–85. This suite of measures can be administered to study participants in two hours or less, in a variety of settings, with a particular emphasis on measuring outcomes in longitudinal epidemiologic studies and prevention or intervention trials. The battery has been normed and validated across the lifespan in subjects age 3-85 and its use ensures that assessment methods and results can be used for comparisons across existing and future studies. The NIH Toolbox is capable of monitoring neurological and behavioral function over time, and measuring key