ICD-10-CM > S00-T88 > T51-T65 > T54 > T54.3 > T54.3X > T54.3X4 T54.3X4 Toxic effect of corrosive alkalis and alkali-like substances, undetermined Non-Billable/Non-Specific Codes T54.3X4A..., initial encounterT54.3X4D..., subsequent encounterT54.3X4S..., sequela