Objectives: To assess the effectiveness of a proactive provider intervention in prompting prior authorization (PA) submissions or provider response prior to PA expiration for medically complex Medicaid patients., Study Design: Pre-post outreach study with data from pharmacy claims and provider outreach., Methods: The intervention and historical comparison (control) groups included expired PAs from December 2019 to February 2020 and from December 2018 to February 2019, respectively. Provider outreach, including telephonic and fax attempts, was conducted over a 2-week period prior to PA expiration. Outcomes were classified as positive or negative based on provider conversation coupled with the result (eg, PA submission) for the intervention group and based solely on pharmacy claims for the control group. The primary end point was the percentage of positive outcomes between the groups, analyzed via χ2 test. The time from PA expiration to the new PA submission was evaluated via t test., Results: A total of 342 outreach attempts were conducted for 270 PAs representing 193 unique patients. Outreach was more likely to result in positive outcomes in the intervention group vs no outreach in the control group (87% vs 25%; P < .00001). On average, PAs were submitted 3.5 days prior to expiration in the intervention group vs 13.0 days after expiration in the control group (t = -7.50; P < .00001)., Conclusions: Proactive outreach resulted in a greater percentage of PA submissions and a significantly reduced time to PA submission. These findings provide important information for payers in guiding clinical programs to enhance continuity of care among at-risk populations.