We evaluated the success of a best practice alert (BPA) in recruiting underrepresented families into an autism spectrum disorder research cohort by comparing BPA-response outcomes ("Interested," "Declined," "Enrolled," "Dismissed") in pediatric primary care practices (TCPs) serving diverse communities with those of subspecialty clinics. Compared to subspecialty clinics, TCPs had higher proportions of Interested responses for patients with private insurance (60.9% vs. 46.2%), "Dismissed" responses for patients with public insurance (30.1% vs. 20.0%), and "Interested" responses for non-white patients (47.7% vs. 33.3%). A targeted BPA can help researchers access more diverse groups and improve equitable representation. However, select groups more often had their alert dismissed, suggesting possible selection bias among some pediatricians regarding who should receive information about study opportunities.