In 2015, the Society for Maternal-Fetal Medicine developed a low risk for cesarean delivery definition based on administrative claims-based diagnosis codes described by the International Classification of Diseases, Ninth Revision, Clinical Modification. The Society for Maternal-Fetal Medicine definition is a clinical enrichment of 2 available measures from the Joint Commission and the Agency for Healthcare Research and Quality measures. The Society for Maternal-Fetal Medicine measure excludes diagnosis codes that represent clinically relevant risk factors that are absolute or relative contraindications to vaginal birth while retaining diagnosis codes such as labor disorders that are discretionary risk factors for cesarean delivery. The introduction of the International Statistical Classification of Diseases, 10th Revision, Clinical Modification in October 2015 expanded the number of available diagnosis codes and enabled a greater depth and breadth of clinical description. These coding improvements further enhance the clinical validity of the Society for Maternal-Fetal Medicine definition and its potential utility in tracking progress toward the goal of safely lowering the US cesarean delivery rate. This report updates the Society for Maternal-Fetal Medicine definition of low risk for cesarean delivery using International Statistical Classification of Diseases, 10th Revision, Clinical Modification coding.