New guidance is offered in the new ICD-10-CM for 2017 that is effective October 1, 2016 on laterality. There have been some questions on which side to assign codes when one side vs. another is being treated or addressed or repaired. These new guideline clarifications can be found below in blue:
B. General Coding Guidelines
When a patient has a bilateral condition and each side is treated during separate encounters, assign the “bilateral” code (as the condition still exists on both sides), including for the encounter to treat the first side. For the second encounter for treatment after one side has previously been treated and the condition no longer exists on that side, assign the appropriate unilateral code for the side where the conditions still exists (e.g., cataract surgery performed on each eye in separate encounters). The bilateral code would not be assigned for the subsequent encounter, as the patient no longer has the condition in the previously treated site. If the treatment on the first side did not completely resolve the condition, then the bilateral code would still be appropriate.