Lynch syndrome (LS) is the most common cause of hereditary colon cancer and has a high risk of endometrial and other cancers. LS is caused by an inherited mutation in one of five genes. Due to the many LS cancer types and the number of genes involved, diagnosing and supporting people with LS is complex, especially in public healthcare. This is the first paper by Canadian LS experts/patient partners providing a framework for the assessment and diagnosis of LS in Canada. It provides guidance for standardized and equitable care and serves as an international resource for LS providers. [By Melyssa Aronson, MS, (C)CGC, https://jmg.bmj.com/content/early/2025/03/11/jmg-2024-110465 ]