Ankylosis of a joint not captured by any other site-specific code in the M24.6x series — meaning fibrous or osseous fusion at a location outside shoulder, elbow, wrist, hand, hip, knee, ankle, or foot.
Verified May 8, 2026 · 4 sources ↓
- Status
- Billable
- Chapter
- 13
- Related CPT
- 8
- Region
- Other
Documentation tips
What should appear in the chart to support M24.69.
Source · Editorial brief grounded in 4 cited references ↓
- Name the specific joint explicitly (e.g., 'sternoclavicular joint ankylosis') — 'other specified' only holds up to audit if the chart identifies a joint not covered by M24.611–M24.676.
- Distinguish true ankylosis (fibrous or osseous fusion with absent or near-absent range of motion) from stiffness; M25.6– applies when motion is limited but fusion is not present.
- Record imaging evidence: plain film, CT, or MRI findings showing joint space obliteration, bony bridging, or fibrous union to support the ankylosis diagnosis over contracture or stiffness.
- Document the etiology when known (post-inflammatory, post-traumatic, post-surgical) — this may add a secondary code and strengthens medical necessity for intervention.
- If a comorbid MCC (e.g., septic arthritis, active rheumatoid arthritis) is documented, ensure it is coded and sequenced correctly to capture DRG 553 rather than DRG 554.
Related CPT procedures
Procedure codes commonly billed with M24.69. 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 M24.69 and adjacent codes.
Source · Editorial brief grounded in CDC ICD-10-CM tabular guidance, AAOS coding references, and cited references ↓
- Defaulting to M24.60 (unspecified joint) when the joint is documented — if the affected joint is identified but has no dedicated site code, M24.69 is required, not M24.60.
- Using M24.69 for spinal ankylosis — the Excludes2 note at M24.6 mandates M43.2– for vertebral joints; M24.69 applied to the spine will trigger an edit.
- Applying M24.69 to the temporomandibular joint — TMJ ankylosis routes to M26.6–, not M24.6x.
- Confusing ankylosis with contracture: M24.59 covers contracture of other specified joints; these are clinically and numerically distinct — verify imaging and clinical findings before selecting.
- Using an injury code (S-code) when ankylosis is an established, chronic condition rather than a current traumatic injury — M24.69 is appropriate for the chronic state; current injuries route elsewhere per the M24 Excludes1 note.
Clinical context
Source · Editorial summary grounded in 4 cited references ↓
M24.69 is the residual 'other specified' code under the M24.6 ankylosis subcategory. Use it only after confirming the affected joint is not already addressed by a more specific sibling code (M24.611–M24.676). Joints that typically land here include the sternoclavicular joint, acromioclavicular joint, sacroiliac joint (when spinal-coding pathway M43.2– does not apply), patellofemoral joint coded separately from the knee series, or small joints of the thorax and ribs. The Excludes1 note at M24.6 bars M25.6– (stiffness without ankylosis) — if the record documents restricted motion but not true bony or fibrous fusion, that note prohibits using M24.69.
The Excludes2 at M24.6 redirects spinal ankylosis to M43.2–, so do not apply M24.69 to vertebral joints. Likewise, temporomandibular joint ankylosis routes to M26.6–, not here. M24.69 was added as a new code effective FY2021 (10/1/2020), distinguishing it from M24.60 (unspecified joint). If the joint is known but simply lacks a dedicated site code, M24.69 is correct; if the joint is genuinely undocumented, use M24.60.
MS-DRG v43.0 groups M24.69 into DRG 553 (Bone diseases and arthropathies with MCC) or DRG 554 (without MCC), matching all other M24.6x codes. Confirm MCC documentation to capture the higher-weighted DRG.
Sibling codes
Other billable codes under M24.6 (laterality / anatomic variants).
Frequently asked questions
Source · Generated from the editorial pipeline, verified against 4 cited references ↓
01When should I use M24.69 instead of M24.60?
02Can M24.69 be used for sacroiliac joint ankylosis?
03Is M24.69 appropriate for post-surgical joint fusion?
04What is the difference between M24.69 and M25.69 (stiffness, other specified joint)?
05Which DRGs does M24.69 map to?
06When was M24.69 added to ICD-10-CM?
07Does M24.69 apply to the temporomandibular joint?
Sources & references
Editorial content was developed using the following public sources. Last verified May 8, 2026.
Mira AI Scribe
The Mira AI Scribe captures the specific joint name, confirmation of fibrous or osseous fusion (not merely stiffness), supporting imaging findings (joint space loss, bony bridging), known etiology, and prior treatment history. That specificity prevents the record from defaulting to the non-billable M24.6 parent or the less-specific M24.60, and closes the audit gap that arises when 'other specified' cannot be substantiated by the clinical note.
See how Mira captures M24.69 documentation