The purpose of this study is to compare the effectiveness of three standard of care outreach approaches (i.e., mailed letter, secure message, and telephone call) on patient adoption of the new 10-year colonoscopy surveillance interval recommendation for a random sample of health plan members who have a now-outdated 5-year surveillance interval due to a finding of 1-2 small adenomas at their prior colonoscopy. The primary study endpoint is the proportion of patients in each outreach arm who adopt the new 10-year colonoscopy surveillance interval.

Inclusion Criteria:

• Kaiser Permanente Northern California (KPNC) membership>12 months
• Primary medical center is either KP San Rafael, KP San Francisco, KP San Leandro, or KP Walnut Creek
• 54-70 years of age at time of 5-year surveillance colonoscopy interval
• A baseline colonoscopy with a finding of 1-2 small tubular adenomas and are due for their 5-year surveillance procedure in 2022
• Average risk for CRC
• A valid mailing address, kp.org account (i.e., KPNC's secure messaging portal), and telephone number at time of study enrollment.

Exclusion Criteria:

• More than 12 months of membership prior to index colonoscopy, and indications that would make an individual above average risk for CRC, such as: adenoma with advanced histology on colonoscopy, adenoma >10 mm on colonoscopy, family history of CRC, prior history of colonoscopy, prior history of adenomas or colon polyp diagnoses, history of IBD, history of hereditary polyposis syndrome, 3 or more adenomas, adenoma 10 mm in size or greater, adenoma with advanced histology, and any sessile serrated polyp or traditional serrated adenoma