ICD-10-CM > S00-T88 > T36-T50 > T48 > T48.9 > T48.99 > T48.996 T48.996 Underdosing of other agents primarily acting on the respiratory system Non-Billable/Non-Specific Codes T48.996A..., initial encounterT48.996D..., subsequent encounterT48.996S..., sequela