ICD-10-CM > S00-T88 > S20-S29 > S23 > S23.4 > S23.42 S23.42 Sprain of sternum Non-Billable/Non-Specific Codes S23.420Sprain of sternoclavicular (joint) (ligament)S23.420A..., initial encounterS23.420D..., subsequent encounterS23.420S..., sequelaS23.421Sprain of chondrosternal jointS23.421A..., initial encounterS23.421D..., subsequent encounterS23.421S..., sequelaS23.428Other sprain of sternumS23.428A..., initial encounterS23.428D..., subsequent encounterS23.428S..., sequelaS23.429Unspecified sprain of sternumS23.429A..., initial encounterS23.429D..., subsequent encounterS23.429S..., sequela