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ICD-10-CM 2027

ICD-10 code for chondrosternal sprain

S23.421

Sprain of chondrosternal joint

Header — needs a more specific code

From the official ICD-10-CM alphabetic index entry “Sprain (joint) (ligament) › chondrosternal”. Page updated September 29, 2026.

About coding chondrosternal sprain

The ICD-10-CM code for chondrosternal sprain is S23.421 (Sprain of chondrosternal joint).

Within S23.42 (sprain of sternum), S23.421 is specifically for sprain of chondrosternal joint. Related codes cover other sprain of sternum (S23.428) and unspecified sprain of sternum (S23.429).

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.

Common questions about chondrosternal sprain ICD-10 codes

What is the ICD-10 code for chondrosternal sprain?

S23.421 — Sprain of chondrosternal joint (a header code; report a more specific subcode).

Is S23.421 billable?

No. S23.421 is a header code. Report one of its more specific subcodes instead.