ICD-10-CM · Other

M67.38

Transient synovitis occurring at a joint site not captured by any other specific M67.3x subcategory — a residual 'other site' designation within the transient synovitis family.

Verified May 8, 2026 · 4 sources ↓

Status: Billable
Chapter: 13
Related CPT: 9
Region: Other

Drawn from CDCCMSICD10Data

Documentation tips

What should appear in the chart to support M67.38.

Source · Editorial brief grounded in 4 cited references ↓

Identify the exact joint or synovial structure by anatomical name — 'temporomandibular joint,' 'sternoclavicular joint,' etc. — so the chart justifies why a site-specific M67.3x code was not available.
Document the clinical basis for 'transient' classification: acute onset, absence of infection (negative joint culture or clinical exclusion), absence of crystal arthropathy, and expected self-limiting course.
Record any imaging findings (ultrasound or MRI showing joint effusion, synovial thickening) and prior conservative management if the visit involves injection or further intervention.
If multiple joints are involved simultaneously, switch to M67.39 (transient synovitis, multiple sites) rather than stacking M67.38 for each location.
Confirm that an infectious etiology has been ruled out; septic arthritis requires a code from the M00 range and cannot be coded as transient synovitis.

Related CPT procedures

Procedure codes commonly billed with M67.38. Linking the right diagnosis to the right procedure is what establishes medical necessity.

Source · CMS LCDs · AAOS specialty guidance · claims-pattern analysis

20550 $60.46

Injection into a single tendon sheath, ligament, or aponeurosis (such as the plantar fascia) — one anatomical site per unit.

20551 $60.46

Injection of a therapeutic substance into the origin or insertion point of a single tendon, used to treat tendinitis, enthesopathy, or localized inflammation at the bone-tendon junction.

20600 $56.11

Needle aspiration and/or injection of a small joint or bursa — such as a finger or toe joint — performed without ultrasound guidance.

20604 $87.18

Arthrocentesis, aspiration and/or injection of a small joint or bursa (e.g., fingers, toes) performed with ultrasound guidance, including permanent image recording and reporting.

20610 $68.81

Aspiration and/or injection of a major joint or bursa (shoulder, hip, knee, or subacromial bursa) performed without ultrasound guidance.

20611 $104.21

Aspiration or injection of a major joint or bursa performed under real-time ultrasound guidance, with permanent image documentation.

27370 View procedure details

76942 View procedure details

77002 View procedure details

Common coding pitfalls

The recurring mistakes coders make with M67.38 and adjacent codes.

Source · Editorial brief grounded in CDC ICD-10-CM tabular guidance, AAOS coding references, and cited references ↓

Using M67.38 when a site-specific code exists: if the affected joint is shoulder, elbow, wrist, hand, hip, knee, or ankle/foot, a lateralized M67.3x code is required — M67.38 is not a laterality-neutral fallback for those joints.
Conflating M67.38 (other site) with M67.39 (multiple sites): M67.38 applies to a single atypical location; use M67.39 when transient synovitis affects two or more joints in the same encounter.
Billing M67.38 without ruling out infectious arthritis — payers may flag the claim if the workup documented in the chart suggests septic joint rather than transient synovitis.
Omitting the specific anatomical site from the note: 'other site' in the code description does not excuse vague documentation; the chart must name the joint to survive audit.

Clinical context

Source · Editorial summary grounded in 4 cited references ↓

M67.38 is the correct code when transient synovitis is documented at a joint that has no dedicated lateralized subcategory under M67.3. The M67.3 family assigns specific codes to shoulder (M67.311/312), elbow (M67.321/322), wrist (M67.331/332), hand (M67.341/342), hip (M67.351/352), knee (M67.361/362), and ankle/foot (M67.371/372). If the affected site falls outside all of those — for example, the temporomandibular joint, the sternoclavicular joint, or a spinal facet joint — M67.38 is the appropriate billable code. M67.39 covers multiple simultaneous sites; M67.38 is for a single 'other' site.

Transient synovitis is a self-limiting inflammatory condition of the synovial lining, typically resolving within weeks. In orthopedic practice it may present as acute joint effusion, warmth, and restricted range of motion without an identifiable infectious, crystalline, or autoimmune cause. When it affects a conventional extremity joint, use the site-specific code; reserve M67.38 for genuinely atypical locations. CMS LCD article A52863 (pain management injections) and draft article DA52863 both list M67.38 as a medical necessity-supporting diagnosis for tendon sheath, ligament, and bursa injection procedures, confirming payer recognition of this code.

Sibling codes

Other billable codes under M67.3 (laterality / anatomic variants).

M67.39

Transient synovitis, multiple sites

M67.30

Transient synovitis, unspecified site

Frequently asked questions

Source · Generated from the editorial pipeline, verified against 4 cited references ↓

01When should I use M67.38 instead of a more specific M67.3x code?

Use M67.38 only when the affected joint has no dedicated subcategory in the M67.3 family. Shoulder, elbow, wrist, hand, hip, knee, and ankle/foot each have their own right/left codes. M67.38 is correct for sites like the temporomandibular, sternoclavicular, or sacroiliac joint.

02Does M67.38 require a laterality modifier?

No. The ICD-10-CM tabular structure does not assign a laterality 6th character to M67.38. Document the side in the clinical note, but the code itself is not split by right/left the way the major-joint subcategories are.

03Can M67.38 support medical necessity for a joint injection?

Yes. CMS LCD article A52863 and draft article DA52863 both explicitly list M67.38 as a covered diagnosis for pain management injections into tendon sheaths, ligaments, bursa, and similar structures.

04What is the difference between M67.38 and M67.39?

M67.38 describes transient synovitis at a single joint that does not fit any named subcategory. M67.39 describes transient synovitis affecting multiple sites simultaneously. Do not use M67.38 multiple times on the same claim to represent bilateral or multi-joint involvement.

05How do I distinguish transient synovitis from septic arthritis at coding time?

The distinction is clinical and must be documented by the provider. If the note documents joint aspiration with negative culture, negative Gram stain, or clinical exclusion of infection, M67.38 is appropriate. If infection has not been excluded or is suspected, codes from the M00 range (infectious arthritis) take precedence and M67.38 should not be used.

06Is M67.38 valid for FY2026 claims?

Yes. M67.38 remains a billable ICD-10-CM code in the FY2026 code set (effective October 1, 2025) with no changes to its description or status from the prior year.

Sources & references

Editorial content was developed using the following public sources. Last verified May 8, 2026.

Mira AI Scribe

Mira AI Scribe captures the specific joint name, onset timeline, effusion characteristics, negative infectious workup, and any imaging findings (effusion on ultrasound or MRI) from the encounter note. That detail prevents the claim from being downcoded to an unspecified synovitis code or flagged for missing medical necessity documentation when paired with an injection procedure code.

See how Mira captures M67.38 documentation