ICD-10-CM > S00-T88 > T66-T78 > T75 > T75.8 > T75.83 T75.83 Effects of war theater Non-Billable/Non-Specific Use Additional code to identify associated manifestations Codes T75.830Gulf war illnessT75.830A..., initial encounterT75.830D..., subsequent encounterT75.830S..., sequelaT75.838Effects of other war theaterT75.838A..., initial encounterT75.838D..., subsequent encounterT75.838S..., sequela