Shoulder impingement syndrome in which the affected side is not specified as right or left in the clinical documentation.

Documentation tips

What should appear in the chart to support M75.40.

Source · Editorial brief grounded in 4 cited references ↓

• Record the affected side (right or left) explicitly in every encounter note — even a single word ('right shoulder impingement') unlocks the more specific M75.41 or M75.42 and reduces audit risk.
• Document objective findings that confirm impingement: positive Neer sign, positive Hawkins-Kennedy sign, painful arc range, and any imaging findings such as subacromial space narrowing or rotator cuff tendinopathy on MRI or ultrasound.
• Note the chronicity and any conservative care already attempted (physical therapy, NSAIDs, prior injections) to support medical necessity for injections, advanced imaging, or surgical consultation.
• If subacromial bursitis or calcific tendinitis coexists, document each condition distinctly so additional M75.3x or M75.5x codes can be reported alongside M75.40.
• For injection encounters (CPT 20610), the note must link the injection site to the impingement diagnosis — document 'subacromial space injection, right shoulder' rather than a generic 'shoulder injection.'

Related CPT procedures

Procedure codes commonly billed with M75.40. 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 M75.40 and adjacent codes.

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

• Using M75.40 when laterality is actually documented in the note — if the provider wrote 'right' or 'left,' code M75.41 or M75.42 instead; payers increasingly query or deny unspecified laterality when the record contains the answer.
• Coding M75.40 alongside a symptom code such as M25.511 (pain in right shoulder) after the impingement diagnosis is established — once the definitive diagnosis is confirmed, the symptom code is redundant and should be dropped.
• Confusing shoulder impingement (M75.4x) with subacromial bursitis (M75.5x) — they are distinct codes and can be reported together if both are documented, but neither should substitute for the other.
• Applying a traumatic injury S-code for impingement when the condition is chronic and degenerative — M75.40 is the correct M-code for non-traumatic/atraumatic presentations; S-codes require an acute mechanism of injury.
• Failing to add a 7th-character extension — M75.40 is an M-code and does not take a 7th character; do not append A, D, or S to this code.

Clinical context

Source · Editorial summary grounded in 4 cited references ↓

Sibling codes

Other billable codes under M75.4 (laterality / anatomic variants).