ImportanceScreening colonoscopy to prevent and early detect colorectal cancer is recommended to be repeated in 10-year intervals, which goes along with high demands of capacities and costs. Evidence of findings at screening colonoscopies conducted 10 or more years after a negative colonoscopy result is sparse, and it remains unclear whether screening colonoscopy intervals could possibly be prolonged.ObjectiveTo assess the prevalence of advanced colorectal neoplasms (ADNs) at least 10 years after a negative screening colonoscopy in a very large cohort of repeated screening colonoscopy participants in Germany.Design, Setting, and ParticipantsThis registry-based cross-sectional study on screening colonoscopy findings reported to the German screening colonoscopy registry during January 2013 to December 2019 included data on screening colonoscopies that were offered to the German general population 55 years or older since 2002; virtually all screening colonoscopies among individuals covered by Statutory Health Insurance (approximately 90% of eligible adults) are reported to the national registry. A total of 120 298 repeat screening colonoscopy participants 65 years or older were identified who had a previous negative screening colonoscopy at least 10 years prior. The findings were compared with all screening colonoscopies conducted at 65 years or older during the same period (1.25 million). The data were analyzed from March to July 2022.Main Outcomes and MeasuresPrevalence of colorectal cancers and ADNs (advanced adenomas and cancers).ResultsOf 120 298 participants, 72 349 (60.1%) were women. Prevalence of ADN was 3.6% and 5.2% among women and men 10 years after a negative screening colonoscopy and gradually increased to 4.9% and 6.6%, respectively, among those who had a negative colonoscopy 14 years or longer prior compared with 7.1% and 11.6% among all screening colonoscopies. Sex-specific and age-specific prevalence of ADNs at repeated colonoscopies conducted 10 or more years after a negative colonoscopy were consistently at least 40% lower among women than among men, lower at younger vs older ages, and much lower than among all screening colonoscopies (standardized prevalence ratios for cancers: 0.22-0.38 among women, 0.15-0.24 among men; standardized prevalence ratios for ADNs: 0.49-0.62 among women, 0.50-0.56 among men).Conclusions and RelevanceThe results of this cross-sectional study suggest that ADN prevalence at screening colonoscopies conducted 10 or more years after a negative screening colonoscopy is low. Extension of the currently recommended 10-year screening intervals may be warranted, especially for female and younger participants without gastrointestinal symptoms.