ICD-10-CM > S00-T88 > S20-S29 > S20 > S20.3 > S20.34 S20.34 External constriction of front wall of thorax Non-Billable/Non-Specific Codes S20.341External constriction of right front wall of thoraxS20.341A..., initial encounterS20.341D..., subsequent encounterS20.341S..., sequelaS20.342External constriction of left front wall of thoraxS20.342A..., initial encounterS20.342D..., subsequent encounterS20.342S..., sequelaS20.343External constriction of bilateral front wall of thoraxS20.343A..., initial encounterS20.343D..., subsequent encounterS20.343S..., sequelaS20.344External constriction of middle front wall of thoraxS20.344A..., initial encounterS20.344D..., subsequent encounterS20.344S..., sequelaS20.349External constriction of unspecified front wall of thoraxS20.349A..., initial encounterS20.349D..., subsequent encounterS20.349S..., sequela