This book is based on the Official Coding Guidelines effective October 1, 2017. This book takes the confusing guidelines and index for External Cause Coding and simplifies them. The book is in three parts: Part 1 defines terms used such as traffic/nontraffic, uncontrolled/controlled fire, and animate/inanimate mechanical forces. Part 2 takes the coding guidelines for external causes and translates them into plain English. The guidelines are then placed into easy to use tables. Part 3 is a simplification of the External Cause Index.