ICD-10-CM > S00-T88 > T20-T25 > T23 > T23.6 > T23.66 > T23.669 T23.669 Corrosion of second degree back of unspecified hand Non-Billable/Non-Specific Codes T23.669A..., initial encounterT23.669D..., subsequent encounterT23.669S..., sequela