Introduction The purpose of this study was to discover the substance use prevalence among physician assistant students (PA-S) compared with the age-relevant general US population and to examine the frequency of stress, burnout, anxiety, and depression during the didactic and clinical phases, while accounting for the impact of the COVID-19 pandemic.Methods A 20-item survey instrument was created. Selfreported data included demographics, anxiety, burnout, tobacco, illicit substances, and prescription medication use. Outcome-based inventories included a modified Perceived Stress Scale, Patient Health Questionnaire-2 (PHQ-2), and Alcohol Use Disorder Identification Test-Concise. The survey was emailed to all US programs (270 programs; 25,000 students), with 54 programs approving dissemination to their students (n4,760). ResultsOf the 1432 responses (30% response rate, 96% completion rate), the final validated sample was 1378 students (56.1% didactic, 43.8% clinical). When compared with the national population, PA-S prevalence for tobacco (5.2%) and illicit substance use (9.9%) were notably lower; alcohol (53.5%) was comparable; and prescription medication (7.0%) is only reported for PA students due to the lack of a national comparison. A higher frequency of substance use was observed during the didactic (52.5%) vs clinical (47.5%) phases. Stress was the dominant factor in both phases (93.5% didactic, 86.1% clinical). Respondents reported that the COVID-19 pandemic had minimal impact on reported rates, other than alcohol.Discussion Although PA-S substance use prevalence is at or below the national population, PA programs are encouraged to review their policies and provide conversations and resources for students who may have one or more risk factors and experience a negative effect from current substance use.