M24.19 captures articular cartilage disorders at joints that don't have a dedicated site-specific code within the M24.1 subcategory — a true 'other specified site' catch-all for non-standard anatomical locations.
Verified May 8, 2026 · 4 sources ↓
- Status
- Billable
- Chapter
- 13
- Related CPT
- 9
- Region
- Other
Documentation tips
What should appear in the chart to support M24.19.
Source · Editorial brief grounded in 4 cited references ↓
- Name the exact joint affected — 'articular cartilage disorder of the acromioclavicular joint' is billable; 'joint cartilage problem' is not sufficient for M24.19.
- Record the imaging or intraoperative finding that confirms cartilage pathology (MRI signal change, arthroscopic grade, plain film joint space narrowing) at the specified non-standard site.
- Confirm in the note that the condition is chronic or non-acute; acute traumatic cartilage injuries should route to the appropriate S-code with 7th character A, not M24.19.
- If laterality is clinically relevant (e.g., right vs. left acromioclavicular joint), document it explicitly — M24.19 has no built-in laterality, so the medical record is the only source of that information.
- Exclude excluded conditions before assigning M24.19: document that chondrocalcinosis, metastatic calcification, and ochronosis have been ruled out or are coded separately if co-present.
Related CPT procedures
Procedure codes commonly billed with M24.19. 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 M24.19 and adjacent codes.
Source · Editorial brief grounded in CDC ICD-10-CM tabular guidance, AAOS coding references, and cited references ↓
- Using M24.19 for knee cartilage disorders when a more specific M24.1 child code (M24.161–M24.169 for knee) or M22.4 (chondromalacia patellae) applies — the knee has dedicated codes and M24.19 should not override them.
- Assigning M24.19 for an acute traumatic chondral injury instead of the appropriate injury S-code; M24.19 is for established, non-acute cartilage disorders.
- Defaulting to M24.19 when the site is simply unspecified rather than 'other specified' — unspecified site should use M24.10, not M24.19.
- Ignoring the Type 2 Excludes note for chondrocalcinosis (M11.1–, M11.2–) and coding M24.19 when the underlying diagnosis is calcium pyrophosphate deposition disease.
- Failing to verify that the joint documented is genuinely outside the M24.1 enumerated sites before using M24.19 — skipping this check invites downcoding or a medical necessity denial.
Clinical context
Source · Editorial summary grounded in 4 cited references ↓
Use M24.19 when the clinician has documented an articular cartilage disorder at a joint that falls outside the explicitly enumerated sites in M24.1 (shoulder, elbow, wrist, hand, hip, knee, ankle, and foot). Examples include the acromioclavicular joint, sternoclavicular joint, sacroiliac joint (non-inflammatory context), or the radiocapitellar joint when the provider has specified the cartilage pathology rather than just joint pain. The code was introduced as a new code in FY2021 and remains active through FY2026.
Before defaulting to M24.19, confirm no site-specific M24.1 child code applies. The M24.1 subcategory carries a Type 2 Excludes note for chondrocalcinosis (M11.1–, M11.2–), internal derangement of knee (M23.–), metastatic calcification (E83.59), and ochronosis (E70.29) — those conditions must be coded elsewhere regardless of joint site. M24.19 does not carry laterality in its structure, so the 'other specified site' itself must be clearly documented in the record to withstand audit.
Common orthopedic scenarios: post-traumatic chondral lesion of the acromioclavicular joint, chondromalacia of the patellofemoral joint when the knee-specific M24.1 codes don't adequately reflect the documented pathology (though M22.4 is preferred for chondromalacia patellae specifically), or cartilage degeneration at a small joint of the thorax. Always query the provider if the site is ambiguous — M24.19 with no site documentation in the chart is an audit vulnerability.
Sibling codes
Other billable codes under M24.1 (laterality / anatomic variants).
Frequently asked questions
Source · Generated from the editorial pipeline, verified against 4 cited references ↓
01What makes a site 'other specified' for M24.19 rather than unspecified?
02Can M24.19 be used for acromioclavicular joint cartilage disorders?
03Should M24.19 be used for chondromalacia patellae?
04Does M24.19 require a 7th character extension?
05What excludes notes apply to the M24.1 subcategory that also affect M24.19?
06When was M24.19 added to ICD-10-CM?
07How does M24.19 interact with acute traumatic cartilage injuries?
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-/M24.19
- 03aapc.comhttps://www.aapc.com/codes/icd-10-codes/M24.19
- 04cms.govhttps://www.cms.gov/medicare-coverage-database/view/article.aspx?articleid=57079&ver=7
Mira AI Scribe
The Mira AI Scribe captures the exact joint name, the nature of the cartilage pathology (degenerative, post-traumatic, fibrillation, etc.), supporting imaging or arthroscopic findings, and confirmation that the affected site is not one of the standard M24.1 enumerated joints. This prevents defaulting to an unspecified-site code (M24.10) or miscoding an acute injury as a chronic disorder — both of which trigger payer scrutiny.
See how Mira captures M24.19 documentation