Systems to address follow-up testing of clinically positive surveillance colonoscopy results are lacking. The impact of an ambulatory safety net (ASN) intervention on rates of colonoscopy completion was assessed. The ASN team identified patients using an electronic registry, conducted patient outreach, coordinated care, and tracked colonoscopy completion. In all, 701 patients were captured in the ASN program: 58.1% (407/701) had possible barriers to follow-up colonoscopy completion, with rates of 80.1% (236/294) if no barrier, and 40.9% (287/701) overall. Colonoscopy completion likelihood increased with prior polypectomy (odds ratio [OR], 1.6; 95% confidence interval [CI], 1.1-2.3), and decreased with White race (OR, 0.5; 95% CI, 0.3-0.9), increased inpatient visits (OR, 0.6; 95% CI, 0.4-0.9), more outreach attempts (OR, 0.6; 95% CI, 0.5-0.7), and fair/poor/inadequate preparation (OR, 0.4; 95% CI, 0.2-0.7) in logistic regression models. An ASN model for quality improvement promotes colonoscopy completion rates and identifies patient barriers.