BACKGROUND - : Although the American Heart Association/American College of Sports Medicine's Preparticipation Questionnaire (AAPQ) is a recommended preexercise cardiovascular screening tool, it has never been systematically evaluated. The purpose of this research is to provide preliminary evidence of its effectiveness among adults aged ≥40 years. METHODS AND RESULTS - : Under the assumption that participants would respond to AAPQ items as they responded to a general health survey, we calculated the sex- and age-specific proportions of adult participants in the National Health and Nutrition Examination Survey 2001 to 2004 who would receive a recommendation for physician consultation based on AAPQ referral criteria. Additionally, we compared recommended AAPQ referrals to a similar assessment using the Physical Activity Readiness Questionnaire in the study sample. AAPQ referral proportions were higher with older age. Across all age groups ≥40 years, 95.5% (94.3% to 96.8%) of women and 93.5% (92.2% to 94.7%) of men in the United States would be advised to consult a physician before exercise. Prescription medication use and age were the most commonly selected items. When referral based on AAPQ was compared with that of the Physical Activity Readiness Questionnaire, the 2 screening tools produced similar results for 72.4% of respondents. CONCLUSIONS - : These results suggest that >90% of US adults aged ≥40 years would receive a recommendation for physician consultation by the AAPQ. Excessive referral may present an unnecessary barrier to exercise adoption and stress the healthcare infrastructure. © 2013 American Heart Association, Inc.