Recurrent dislocation of a joint where the specific joint has not been documented or identified in the medical record.
Verified May 8, 2026 · 5 sources ↓
- Status
- Billable
- Chapter
- 13
- Related CPT
- 9
- Region
- General
Documentation tips
What should appear in the chart to support M24.40.
Source · Editorial brief grounded in 5 cited references ↓
- Identify the specific joint by name in every note — shoulder, knee, hip, ankle, etc. — to avoid landing on M24.40 instead of a site-specific M24.41–M24.47x code.
- Document laterality explicitly (right vs. left); if joint is named but side is omitted, you still drop to an 'unspecified' laterality code rather than M24.40.
- Distinguish recurrent/chronic instability from acute traumatic dislocation — the latter requires an S-code with a 7th-character extension, not M24.40.
- Note whether the condition involves subluxation (partial) or full dislocation; both are captured under M24.4x per the 'Applicable To' note in the Tabular List.
- Exclude patellar and vertebral recurrent dislocations from this code family — route those to M22.0–M22.1 and M43.3–M43.5x respectively and document accordingly.
Related CPT procedures
Procedure codes commonly billed with M24.40. Linking the right diagnosis to the right procedure is what establishes medical necessity.
Source · CMS LCDs · AAOS specialty guidance · claims-pattern analysis
Common coding pitfalls
The recurring mistakes coders make with M24.40 and adjacent codes.
Source · Editorial brief grounded in CDC ICD-10-CM tabular guidance, AAOS coding references, and cited references ↓
- Using M24.40 when the joint is clearly documented: if the note names the joint, a site-specific M24.41–M24.47x code is required — M24.40 is not a valid shortcut.
- Coding M24.40 for an acute first-time dislocation; acute traumatic dislocations belong in the S-code injury chapter, not M24.4x.
- Failing to check the patellar and vertebral exclusions — recurrent patellar dislocation goes to M22.0–M22.1 and recurrent vertebral dislocation to M43.3–M43.5x, not M24.4x.
- Confusing 'unspecified joint' (M24.40) with 'other specified joint' (M24.49) — if the joint is known but does not have a dedicated subcategory, use M24.49, not M24.40.
Clinical context
Source · Editorial summary grounded in 5 cited references ↓
M24.40 is the last-resort code in the M24.4x family — use it only when the provider's documentation genuinely fails to name the affected joint. The M24.4 category covers chronic, habitual, or recurrent dislocation and includes recurrent subluxation of a joint. It excludes recurrent patellar dislocation (M22.0–M22.1) and recurrent vertebral dislocation (M43.3–M43.5–), which have their own code families.
In practice, M24.40 should be rare in an orthopedic setting. Every orthopedic note should name the joint. If documentation specifies shoulder, elbow, wrist, hand/finger, hip, knee, or ankle/foot/toe, drop to the appropriate site-specific code (M24.41–M24.47x). If laterality is known but the joint is somehow unlisted in those subcategories, use M24.49 (other specified joint). Reserve M24.40 for the uncommon scenario where the joint truly cannot be determined from the record — for example, a referral note or external record with incomplete information.
M24.40 also does not apply to acute traumatic dislocations; those are coded from the injury chapter (S-codes with 7th-character A/D/S). Current injury is explicitly excluded from category M24 per the Tabular List. Code M24.40 reflects a chronic, established pattern of instability, not a first-time or acute event.
Sibling codes
Other billable codes under M24.4 (laterality / anatomic variants).
Frequently asked questions
Source · Generated from the editorial pipeline, verified against 5 cited references ↓
01When is M24.40 actually appropriate to use?
02Can M24.40 be used for a first-time dislocation?
03Does M24.40 cover recurrent patellar dislocation?
04What is the difference between M24.40 and M24.49?
05Does M24.40 include recurrent subluxation?
06Are spinal recurrent dislocations coded to M24.40?
07Which CPT procedures commonly pair with M24.4x codes?
Sources & references
Editorial content was developed using the following public sources. Last verified May 8, 2026.
- 01CDC ICD-10-CM Tabular List 2026 (effective Oct 1, 2025)
- 02icd10data.comhttps://www.icd10data.com/ICD10CM/Codes/M00-M99/M20-M25/M24-/M24.40
- 03icd10data.comhttps://www.icd10data.com/ICD10CM/Codes/M00-M99/M20-M25/M24-
- 04aapc.comhttps://www.aapc.com/codes/icd-10-codes/M24.40
- 05cms.govhttps://www.cms.gov/files/document/fy-2024-icd-10-cm-coding-guidelines-updated-02/01/2024.pdf
Mira AI Scribe
Mira captures the joint name, laterality, duration and pattern of instability events, any prior reduction history, and imaging findings (e.g., Hill-Sachs lesion, labral tear, ligamentous laxity on MRI) from the encounter note. That specificity prevents M24.40 — the unspecified-joint fallback — and drives correct site-specific coding, reducing audit exposure for unspecified diagnosis codes on surgical or therapy claims.
See how Mira captures M24.40 documentation