ICD-10-CM · Knee

M76.31

Iliotibial band syndrome affecting the right leg, classified under lower limb enthesopathies, characterized by friction-related inflammation where the IT band crosses the lateral femoral epicondyle.

Verified May 8, 2026 · 6 sources ↓

Status: Billable
Chapter: 13
Related CPT: 10
Region: Knee

Drawn from CDCICD10DataAAPCOrthoInfoIcdcodes

Documentation tips

What should appear in the chart to support M76.31.

Source · Editorial brief grounded in 6 cited references ↓

Explicitly document 'right leg' or 'right knee' — 'lateral knee pain' alone does not support M76.31 over M76.30.
Record the provocative test results by name: Ober test, Noble compression test, or pain at 30° knee flexion are standard clinical validators for ITBS.
Note any imaging ordered (MRI or ultrasound) and relevant findings such as IT band thickening or lateral compartment signal change to substantiate medical necessity.
Document activity history (mileage increases, sport, occupational demands) to support the overuse mechanism and justify conservative treatment authorization.
If bilateral ITBS is present, document both sides explicitly so both M76.31 and M76.32 can be coded — a single unspecified code will underrepresent the clinical picture.
Record prior conservative care (rest, physical therapy, NSAIDs, injections) and patient response when escalating to advanced imaging or procedural intervention.

Related CPT procedures

Procedure codes commonly billed with M76.31. Linking the right diagnosis to the right procedure is what establishes medical necessity.

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

27330 $412.84

Open knee arthrotomy performed solely to obtain a synovial tissue sample for pathologic examination.

27331 $459.60

Open arthrotomy of the knee joint for exploration, biopsy, or removal of loose or foreign bodies.

20610 $68.81

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

97110 $29.06

Therapeutic exercise billed per 15-minute unit, targeting strength, endurance, range of motion, or flexibility with direct one-on-one patient contact.

73721 $204.41

MRI of a lower extremity joint (hip, knee, or ankle) performed without contrast material.

29530 $28.72

Application of adhesive or non-adhesive strapping material to stabilize or support the knee joint.

27599 View procedure details

97530 View procedure details

76881 View procedure details

97012 View procedure details

Common coding pitfalls

The recurring mistakes coders make with M76.31 and adjacent codes.

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

Coding M76.30 (unspecified) when the provider has documented the right side in the note — always assign the most specific laterality code supported by documentation.
Confusing ITBS with lateral collateral ligament sprain or lateral meniscus pathology; the IT band runs external to the joint capsule and does not code to meniscal or ligamentous codes.
Omitting an external cause code when the condition is directly linked to a documented occupational or sports activity, as required by Chapter 13 instructional notes.
Using an S-code (injury chapter) for a chronic or overuse presentation — M76.31 is the correct home for repetitive-use ITBS; S-codes apply to acute traumatic injuries.
Billing M76.31 for left-leg symptoms documented in the same encounter without also adding M76.32 — each affected side requires its own code.

Clinical context

Source · Editorial summary grounded in 6 cited references ↓

M76.31 is the billable code for iliotibial band syndrome (ITBS) confirmed in the right leg. It sits under parent code M76.3 (Iliotibial band syndrome) within the M76 Enthesopathies, lower limb, excluding foot block. Use M76.31 only when the provider has documented right-leg laterality — either explicitly stated or supported by exam findings. If laterality is absent from the documentation, default to M76.30 (unspecified leg). Bilateral involvement requires both M76.31 and M76.32; there is no single bilateral code in this subcategory.

ITBS is a repetitive-use soft tissue disorder most common in runners, cyclists, and military personnel. The classic clinical presentation is lateral knee pain reproduced at approximately 30° of knee flexion, tenderness over the lateral femoral epicondyle, and a positive Ober test. MRI findings of IT band thickening or lateral compartment edema support but are not required for diagnosis. The condition is grouped under MS-DRG 557 (Tendonitis, myositis and bursitis with MCC) and MS-DRG 558 (without MCC) for inpatient purposes.

Conservative management — rest, physical therapy, NSAIDs, corticosteroid injection — is the standard first-line approach. Surgical release is rare but exists for refractory cases. When the injury is attributable to a specific external cause (e.g., occupational overuse or a sporting event), ICD-10-CM Chapter 13 instructs coders to append an external cause code after M76.31.

Sibling codes

Other billable codes under M76.3 (laterality / anatomic variants).

M76.32

Iliotibial band syndrome, left leg

M76.30

Iliotibial band syndrome, unspecified leg

Frequently asked questions

Source · Generated from the editorial pipeline, verified against 6 cited references ↓

01When should I use M76.31 versus M76.30?

Use M76.31 whenever the provider documents right-leg laterality. M76.30 is reserved for encounters where laterality genuinely cannot be determined after clinical workup — not simply because the coder didn't see it documented. Query the provider if unclear.

02How do I code bilateral IT band syndrome?

Code both M76.31 (right) and M76.32 (left). There is no standalone bilateral code in the M76.3 subcategory. Sequence based on the primary reason for the encounter or the side that drove the visit.

03Is M76.31 appropriate for an acute IT band injury during a race, or only for chronic overuse?

M76.31 covers both presentations when the provider diagnoses iliotibial band syndrome. If the provider instead documents an acute traumatic tear or rupture of the iliotibial band, review S-codes for soft tissue injury of the knee region — but classic ITBS, even with acute flare, stays at M76.31.

04Do I need imaging to support M76.31?

No — ITBS is a clinical diagnosis. Imaging (MRI, ultrasound) is supportive and strengthens the record for medical necessity reviews, but the code is valid based on documented clinical findings and a confirmed diagnosis from the provider.

05Should I add an external cause code when billing M76.31 for a runner?

Yes, when the overuse mechanism is documented. ICD-10-CM Chapter 13 instructs coders to append an external cause code to identify the activity or cause — for example, a sports activity code from the Y93 category — following M76.31.

06What MS-DRGs does M76.31 map to for inpatient claims?

M76.31 groups to MS-DRG 557 (Tendonitis, myositis and bursitis with MCC) or MS-DRG 558 (without MCC) under MS-DRG v43.0. The presence or absence of a major complication or comorbidity drives the split.

07Can M76.31 be used alongside a patellofemoral pain code or lateral meniscus code?

Yes, if both conditions are documented and clinically distinct. ITBS involves the IT band at the lateral femoral epicondyle and is anatomically separate from patellofemoral or meniscal pathology. Code all confirmed diagnoses supported by documentation.

Sources & references

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

Mira AI Scribe

Mira AI Scribe captures laterality (right leg), the specific anatomical location of pain (lateral femoral epicondyle or lateral knee), provocative test results (Ober test, Noble compression, pain at 30° flexion), relevant activity history, and any imaging findings such as IT band thickening on MRI or ultrasound. Capturing these elements prevents downcoding to M76.30 (unspecified) and provides the clinical narrative needed to defend medical necessity for physical therapy, corticosteroid injection, or advanced imaging on audit.

See how Mira captures M76.31 documentation