Medial epicondylitis of the left elbow — degenerative tendinopathy at the origin of the flexor-pronator muscle group on the medial epicondyle of the left humerus, commonly called golfer's elbow or pitcher's elbow.

Documentation tips

What should appear in the chart to support M77.02.

Source · Editorial brief grounded in 6 cited references ↓

• Explicitly name the affected side — 'left elbow' — in the assessment; 'elbow pain' alone forces a drop to M77.00 (unspecified).
• Record the clinical findings that confirm the diagnosis: medial epicondyle point tenderness, pain with resisted wrist flexion or forearm pronation, and grip-strength deficit if present.
• If ultrasound or MRI is ordered, summarize key findings (tendon hypoechogenicity, partial-thickness tearing, calcific deposits) to support medical necessity for imaging and injection CPTs.
• Document conservative care already attempted (physical therapy, NSAIDs, activity modification, prior injections) — payers and LCDs may require this before approving corticosteroid injection or surgical intervention.
• Note acuity and chronicity (acute flare vs. chronic overuse) and any occupational or sport-related etiology; this context strengthens medical necessity documentation.
• If both elbows are affected, document each side separately and assign both M77.01 and M77.02 — a single bilateral synonym does not replace laterality-specific coding on the claim.

Related CPT procedures

Procedure codes commonly billed with M77.02. 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 M77.02 and adjacent codes.

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

• Assigning M77.00 (unspecified elbow) when the note clearly states 'left' — always code to the highest specificity the documentation supports.
• Confusing M77.02 (medial epicondylitis, left) with M77.12 (lateral epicondylitis, left) — medial involves the flexor-pronator origin; lateral involves the extensor origin (ECRB); the anatomical side in the note must match the code selected.
• Using M77.02 for a right-elbow diagnosis — the 2 in the 6th character position designates left; right elbow is M77.01.
• Pairing M77.02 with elbow pain codes (M25.522) once the specific enthesopathy diagnosis is confirmed — symptom codes are redundant and can trigger edits.
• Failing to add the RT/LT modifier on injection CPTs (e.g., 20550, 20600) when the diagnosis code already specifies left — both laterality indicators are expected on the claim.
• Appending a 7th-character extension (A, D, S) to M77.02 — this is an M-code and does not take encounter-type suffixes.

Clinical context

Source · Editorial summary grounded in 6 cited references ↓

Sibling codes

Other billable codes under M77.0 (laterality / anatomic variants).