Introduction: Gallstones are the most common etiology of acute pancreatitis (AP). Endoscopic retrograde cholangiopancreatography (ERCP) with sphincterotomy and/or stone extraction could be beneficial in preventing recurrence. Previous trials showed no effect on in-hospital outcomes such as mortality, complications, severity, and length of stay. We examined the association between ERCP during an admission for AP due to gallstones and later emergent encounters and readmissions for recurrent pancreatitis. Methods: We performed a retrospective cohort study using the Truven Health Marketscan Databases from 2008-2014, which capture clinical utilization across inpatient and outpatient settings for subjects with employer-based health insurance. All admissions with a primary diagnosis of AP and concomitant codes for gallstones were extracted. Details regarding inpatient admissions, outpatient services, demographic variables, comorbidities, severity of AP, and cholecystectomy (CCY) status were collected. The exposure was having undergone an ERCP with sphincterotomy and/or stone extraction during the admission. The primary outcome of interest was persistent/recurrent pancreatitis following discharge from the index admission. Cox proportional hazards models were used to examine the association between therapeutic ERCP and the primary outcome, while adjusting for covariates. Propensity score adjustment with clustering was used to more fully examine this association with respect to CCY status. Results: 17,348 patients met inclusion criteria, of whom 3,375 (19.5%) underwent a therapeutic ERCP. Compared to those without therapeutic ERCP, patients with therapeutic ERCP tended to be female, have fewer comorbidities, and have longer length of stay (Table). Adjusting for patient characteristics, comorbidities, severity of AP, clinical factors, and CCY status as a time-varying covariate, patients undergoing therapeutic ERCP had a lower hazard of recurrent pancreatitis (HR 0.71, 95% CI 0.59-0.84). This was especially true for patients who had not undergone CCY (HR 0.45, 95% CI 0.30-0.68), but not after CCY (HR 0.96, 95% CI 0.66-1.39) (Figure 1 and 2).Figure: Kaplan-Meier survival curve of recurrent pancreatitis by therapeutic ERCP status for patients who were pre-cholecystectomy at any point in time following discharge, adjusted for patient demographics, comorbidities, and severity of pancreatitis by inverse probability-weighting of therapeutic ERCP via propensity scores.Figure: Kaplan-Meier survival curve of recurrent pancreatitis by therapeutic ERCP status for patients who were post-cholecystectomy at any point in time following discharge, adjusted for patient demographics, comorbidities, and severity of pancreatitis by inverse probability-weighting of therapeutic ERCP via propensity scores.Table: Table. Distribution of demographic and clinical variables for patients in the study with respect to whether they received a therapeutic ERCP.Conclusion: In this large, national study examinng long-term outcomes of ERCP in patients with AP due to gallstones, therapeutic ERCP was associated with reduction in recurrent pancreatitis, especially in those patients discharged without CCY. Therapeutic ERCP should be considered in all such patients who cannot undergo CCY during their index admission.