ICD-10-CM > V00-Y99 > Y35-Y38 > Y36 > Y36.7 > Y36.7X > Y36.7X1 Y36.7X1 War operations involving chemical weapons and other forms of unconventional warfare, civilian Non-Billable/Non-Specific Codes Y36.7X1A..., initial encounterY36.7X1D..., subsequent encounterY36.7X1S..., sequela