ICD-10-CM > S00-T88 > S20-S29 > S21 > S21.0 > S21.05 S21.05 Open bite of breast Non-Billable/Non-Specific Applicable To Bite of breast NOS Type 1 Excludes superficial bite of breast (S20.17) Codes S21.051Open bite of right breastS21.051A..., initial encounterS21.051D..., subsequent encounterS21.051S..., sequelaS21.052Open bite of left breastS21.052A..., initial encounterS21.052D..., subsequent encounterS21.052S..., sequelaS21.059Open bite of unspecified breastS21.059A..., initial encounterS21.059D..., subsequent encounterS21.059S..., sequela