Patient navigation (PN) has been shown to improve participation in cancer screening, including colorectal cancer screening, and the Community Preventive Services Task Force now recommends the practice. Despite the effectiveness of PN programs, little is known about the number of contacts needed to successfully reach patients or about the demographic and healthcare utilization factors associated with reach. PRECISE was an individual randomized study of PN vs. usual care conducted as a partnership between two large health systems in the Pacific Northwest. The navigation program was a six topic-area telephonic program designed to support patients with an abnormal fecal test result to obtain a follow-up colonoscopy. We report the number of contact attempts needed to successfully reach navigated patients. We used logistic regression to report the demographic and healthcare utilization characteristics associated with patients allocated to PN who were successfully reached. We identified 1200 patients with an abnormal FIT result, among whom 970 were randomized into the study (45.7% were female, 17.5% were Spanish-speaking, mean age was 60.8). Of the 479 patients allocated to the PN intervention, 382 (79.7%) were reached within 18 call attempts and nearly all (n = 356; 93.2%) were reached within six contact attempts. Patient characteristics associated with reach were race, county of residence, and body mass index. Our findings can guide future efforts to optimize the reach of PN programs.