OBJECTIVES: Incomplete subspecialty referrals, whether unscheduled or unattended, represent unmet patient needs and an opportunity to improve patient safety and experiences. Our objectives were to describe the rates of appointment scheduling and visit attendance after pediatric subspecialty referral and to examine patient and systems factors associated with scheduled referrals and attended appointments. METHODS: We conducted a retrospective review of referrals within a network of 52 primary and urgent care sites from November 2016 to October 2017. We included referrals for children ≤17 years old referred to medical or surgical subspecialists. We examined patient and health systems factors associated with (1) appointment scheduling and (2) visit attendance. RESULTS: Of 20 466 referrals, 13 261 (65%) resulted in an appointment scheduled within 90 days and 10 514 (51%) resulted in a visit attended within 90 days. In adjusted analyses, referral to surgical subspecialists was associated with an increased likelihood of appointment scheduling but a decreased likelihood of visit attendance. Compared with appointments scheduled within 7 days, appointments with intervals from referral to scheduled appointment exceeding 7 days were associated with decreasing likelihood of visit attendance (adjusted odds ratio 8-14 days 0.48; 95% confidence interval 0.37-0.61). Patient factors associated with decreased likelihood of both appointment scheduling and visit attendance included African American race, public insurance, and lower zip code median income. CONCLUSIONS: Patient and system factors were associated with variation in appointment scheduling and visit attendance. Decreased interval to appointment was significantly associated with visit attendance. These factors represent targets for interventions to improve referral completion.