ICD-10-CM > S00-T88 > T36-T50 > T39 > T39.1 > T39.1X > T39.1X6 T39.1X6 Underdosing of 4-Aminophenol derivatives Non-Billable/Non-Specific Codes T39.1X6A..., initial encounterT39.1X6D..., subsequent encounterT39.1X6S..., sequela