ICD-10-CM 2027
ICD-10 code for sternum sprain
From the official ICD-10-CM alphabetic index entry “Sprain (joint) (ligament) › sternum”. Page updated September 29, 2026.
About coding sternum sprain
The ICD-10-CM code for sternum sprain is S23.429 (Unspecified sprain of sternum). The official index lists 3 more specific codes, so check the documentation for details such as type, cause, site or severity before settling on S23.429.
Within S23.42, choose S23.429 (Unspecified sprain of sternum) only when documentation doesn't support a more specific option: sprain of chondrosternal joint (S23.421) and other sprain of sternum (S23.428).
Codes in this range require a 7th character: A for initial encounter, D for subsequent encounter and S for sequela. Use placeholder "X" characters to fill any empty positions before the 7th character.
It has been part of ICD-10-CM since the code set took effect on October 1, 2015 and hasn't changed since.
More specific sternum sprain codes (official index)
Common questions about sternum sprain ICD-10 codes
What is the ICD-10 code for sternum sprain?
- S23.429 — Unspecified sprain of sternum (a header code; report a more specific subcode). More specific codes apply when the documentation supports them: S23.421, S23.428, S43.6.
What is the ICD-10 code for chondrosternal joint sternum sprain?
- S23.421 — Sprain of chondrosternal joint (header code; choose a more specific subcode).
What is the ICD-10 code for sternoclavicular sternum sprain?
- S43.6 — Sprain of sternoclavicular joint (header code; choose a more specific subcode).
Is S23.429 billable?
- No. S23.429 is a header code. Report one of its more specific subcodes instead.