["Journal of Applied Behavior Analysis, Volume 59, Issue 4, Autumn 2026. ", "\nAbstract\nThe Step it UP! Game, a modified version of the Good Behavior Game, has been implemented to increase physical activity levels among elementary school children and adults with disabilities. The purpose of the current study was to evaluate Step it UP! Game sessions that differed in duration within a given reinforcement arrangement on steps. Participants included young adults with disabilities (n = 15). Six conditions were alternated randomly within a multielement design: baseline (10, 20, and 40 min) and Step it UP! Game (10, 20, and 40 min). Participants took more steps during the Step it UP! Game relative to baseline, but no clear step differences were observed across game conditions. Pauses in step taking and the percentage of time engaging in moderate‐intensity physical activity changed as game duration was manipulated.\n"]