ICD-10-CM > S00-T88 > T36-T50 > T42 > T42.8 > T42.8X > T42.8X6 T42.8X6 Underdosing of antiparkinsonism drugs and other central muscle-tone depressants Non-Billable/Non-Specific Codes T42.8X6A..., initial encounterT42.8X6D..., subsequent encounterT42.8X6S..., sequela