Background: Improving the quality of health care is a national priority, and providing patient-centered care is one of the 6 key areas for quality improvement. In the setting of patients with young-onset colorectal cancer (CRC), appropriate genetic workup and testing for potential underlying inherited CRC syndromes is fundamental to patient-centered care. Lynch syndrome (LS) is the most common of these inherited syndromes, and current recommendations from the NCCN and other professional societies advocate universal screening for LS among young patients with CRC. However, practical implementation of these guidelines often falls short. Methods: We conducted a prospective quality improvement intervention trial to optimize universal screening for LS in young (age <50 years) patients, involving 356 eligible patients during the 12-month preintervention period and 299 patients during the postintervention. Results: Applying the Six Sigma conceptual framework, we demonstrated a significant increase in use of tumor-based molecular testing and subsequent confirmatory germline mutation testing for LS. This led to identification of more patients to be managed as having LS and of more first- and second-degree relatives to benefit from the testing results. Conclusions: This study demonstrated the successful application of a quality improvement conceptual framework for the universal adoption of molecular biomarker testing in patients with cancer, and for improving adherence to NCCN Clinical Practice Guidelines in Oncology for CRC Screening. As molecular and genetic testing is becoming increasingly common, we present a prototype study for improving the adoption of molecular studies and the provision of guideline-based patient-centered care.