ICD-10-CM > S00-T88 > T36-T50 > T46 > T46.2 > T46.2X > T46.2X6 T46.2X6 Underdosing of other antidysrhythmic drugs Non-Billable/Non-Specific Codes T46.2X6A..., initial encounterT46.2X6D..., subsequent encounterT46.2X6S..., sequela