Question: One of our pediatricians recently performed a reduction of a traumatic fracture in our office. I want to bill an evaluation and management (E/M) service with the reduction code using the fracture diagnosis code, but should I also include an external cause code? If so, should I attach it to the E/M or the reduction procedure code? Michigan Subscriber Answer: ICD-10 guidelines for the Chapter 20: External Causes of Morbidity (V00-Y99) codes tell you that “there is no national requirement for mandatory ICD-10-CM external cause code reporting.” However, the guidelines go on to tell you that “unless a provider is subject to a state-based external cause code reporting mandate or these codes are required by a particular payer, reporting [these codes] is not required.” Payers especially may want you to report external cause codes to establish liability in cases where the patient’s injury occurred in a location such as a school or municipal playground, where use of the code could shift responsibility for payment from the carrier to the owner of the place of occurrence. So, you will need to determine if you are mandated to report the external cause or not. Even if you are not, there may be other good reasons to report an external cause. Payers may want to see an external cause code to justify whether the level of care your pediatrician has provided is appropriate. They may also expedite claims with external cause codes. And, regardless of mandates, reporting external causes is important as it provides “valuable data for injury research and evaluation of injury prevention strategies,” according to ICD-10 guidelines. No guideline exists as to whether you should attach an external cause code to an E/M service or a procedure code. However, there are plenty of other ICD-10 guidelines that you follow in order to report them correctly: