W99Exposure to other man-made environmental factors

W99 is the ICD-10-CM diagnosis code for exposure to other man-made environmental factors. It belongs to block W85-W99 (exposure to electric current, radiation and extreme ambient air temperature and pressure) and chapter 20 (external causes of morbidity). It is a header code, so it can't be reported by itself; one of its 3 subcodes must be used instead.

To report this condition, pick the subcode that matches the documentation: W99.XXXA (initial encounter), W99.XXXD (subsequent encounter) and W99.XXXS (sequela).

It has been part of ICD-10-CM since the code set took effect on October 1, 2015 and hasn't changed since.