ICD-10-CM > S00-T88 > T36-T50 > T48 > T48.4 > T48.4X > T48.4X6 T48.4X6 Underdosing of expectorants Non-Billable/Non-Specific Codes T48.4X6A..., initial encounterT48.4X6D..., subsequent encounterT48.4X6S..., sequela