Using cross-sectional data from national surveys and prescription records between 2019 and 2022, this study found that among U.S. adults ages 18-64 who used prescription stimulants, 25.3% reported nonmedical use and 9.0% met criteria for prescription stimulant use disorder (PSUD), with highest prevalence linked to amphetamine use, highlighting the need for PSUD screening and treatment regardless of reported use patterns.