M22.1 vs M23

M22.1 (Recurrent subluxation of patella) compared with M23 (Internal derangement of knee), from the official CMS tabular data. Both may be reported when both conditions are documented (Excludes2).

Can these codes be reported together?

Yes, when both are documented. M23 carries an Excludes2 note covering M22.1: “recurrent dislocation or subluxation of patella (M22.0-M22.1)”

Excludes2 marks distinct conditions — both may be reported when both are documented.

Side by side

	M22.1Recurrent subluxation of patella	M23Internal derangement of knee
Billing status	Non-billable header Report instead: M22.10, M22.11, M22.12	Non-billable header Report instead: M23.000, M23.001, M23.002, M23.003, M23.004
Classification	M00-M99 — Diseases of the Musculoskeletal System and Connective Tissue (M00-M99)	M00-M99 — Diseases of the Musculoskeletal System and Connective Tissue (M00-M99)
Definition	Recurrent subluxation of patella is a non-billable ICD-10-CM category code (M22.1).	Internal derangement of knee is a non-billable ICD-10-CM category code (M23).
Includes	Incomplete dislocation of patella	—

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Derived from the official CMS ICD-10-CM tabular data (FY2026). Not billing advice; verify sequencing rules for the encounter. All data sources