ICD-10-CM > S00-T88 > T36-T50 > T47 > T47.9 > T47.96 T47.96 Underdosing of unspecified agents primarily affecting the gastrointestinal system Non-Billable/Non-Specific Codes T47.96XA..., initial encounterT47.96XD..., subsequent encounterT47.96XS..., sequela