ICD-10-CM > S00-T88 > S20-S29 > S21 > S21.0 > S21.00 S21.00 Unspecified open wound of breast Non-Billable/Non-Specific Codes S21.001Unspecified open wound of right breastS21.001A..., initial encounterS21.001D..., subsequent encounterS21.001S..., sequelaS21.002Unspecified open wound of left breastS21.002A..., initial encounterS21.002D..., subsequent encounterS21.002S..., sequelaS21.009Unspecified open wound of unspecified breastS21.009A..., initial encounterS21.009D..., subsequent encounterS21.009S..., sequela