M75.90

M75.90 identifies a shoulder lesion that is both unspecified in type and unspecified in laterality — the catch-all within the M75.9 subcategory when neither the nature of the lesion nor the affected side is documented.

Verified May 8, 2026 · 5 sources ↓

Status: Billable
Chapter: 13
Related CPT: 16
Region: Shoulder

Drawn from CDCAAPCCMS

Documentation tips

What should appear in the chart to support M75.90.

Source · Editorial brief grounded in 5 cited references ↓

Always document laterality by name (right or left shoulder) — this alone upgrades the code from M75.90 to M75.91 or M75.92 and demonstrates higher specificity.
Record the specific lesion type when identifiable: adhesive capsulitis, impingement syndrome, rotator cuff tear, bursitis, calcific tendinitis — each has its own M75 subcategory that outranks M75.90.
Document whether the condition is traumatic or non-traumatic in onset; traumatic injuries require S-codes with 7th-character encounter extensions, not M75 codes.
Include supporting diagnostic findings — MRI findings, ultrasound results, or physical exam signs — that may allow the lesion to be classified more specifically on a subsequent visit.
If the lesion type cannot yet be determined (e.g., initial presentation pending imaging), note that in the record so M75.90 is defensible as a temporary placeholder rather than a chronic coding habit.

Related CPT procedures

Procedure codes commonly billed with M75.90. Linking the right diagnosis to the right procedure is what establishes medical necessity.

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

29806 $972.97

Arthroscopic surgical repair or tightening of the shoulder joint capsule to correct instability or recurrent dislocation.

29807 $951.93

Arthroscopic surgical repair of a superior labrum anterior and posterior (SLAP) lesion of the shoulder joint.

29819 $550.11

Arthroscopic shoulder surgery for removal of loose or foreign bodies from the joint

29820 $501.68

Arthroscopic surgical removal of part of the synovial lining of the shoulder joint (partial synovectomy).

29821 $557.46

Arthroscopic surgical removal of the entire shoulder joint synovial lining (complete synovectomy), performed endoscopically.

29822 $516.04

Arthroscopic shoulder surgery with limited debridement of one or two discrete structures within the shoulder joint.

29823 $558.80

Arthroscopic surgical debridement of the shoulder involving three or more discrete anatomic structures.

29824 $638.96

Arthroscopic resection of the distal clavicle including its articular surface, performed at the acromioclavicular joint (the Mumford procedure).

29825 $553.45

Arthroscopic shoulder surgery to cut and remove adhesions restricting joint motion, with or without manipulation of the shoulder

29827 $976.31

Arthroscopic surgical repair of the rotator cuff, performed entirely through the shoulder joint via endoscopic technique.

29828 $843.71

Arthroscopic shoulder surgery involving tenodesis of the long head of the biceps tendon — the tendon is detached from its origin and reanchored to a new fixation point, performed entirely through arthroscopic portals.

73221 $205.08

MRI of any upper extremity joint — shoulder, elbow, or wrist — performed without contrast material.

73222 $312.63

MRI of an upper extremity joint performed with contrast material — covers shoulder, elbow, wrist, or hand joints.

73030 $35.74

Radiologic examination of the shoulder requiring a minimum of two views, reported as a single unit regardless of how many views are obtained.

73010 $25.05

Radiologic examination of the scapula (shoulder blade), complete — capturing all standard views needed to evaluate fractures, dislocations, bone lesions, or structural abnormalities of the scapula.

73223 View procedure details

Common coding pitfalls

The recurring mistakes coders make with M75.90 and adjacent codes.

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

Using M75.90 when laterality is documented: if the chart says 'right' or 'left,' you must code M75.91 or M75.92 — M75.90 is only for genuinely unspecified side.
Defaulting to M75.90 instead of working through M75 subcategories: impingement (M75.4-), bursitis (M75.5-), and rotator cuff pathology (M75.1-) all have their own codes and should be used when the lesion type is identified.
Applying M75.90 to traumatic shoulder injuries: acute trauma (fall, direct blow, sudden mechanism) requires an S-code with the appropriate 7th character (A, D, or S), not an M-code.
Leaving M75.90 on the claim after imaging confirms a specific diagnosis: once MRI or arthroscopy identifies the lesion, update the code — continuing to bill an unspecified code after a specific diagnosis is established constitutes undercoding.
Confusing M75.90 with M75.80: M75.80 is 'other shoulder lesions, unspecified shoulder' — used when the lesion is known but doesn't fit a named subcategory, not when the lesion type is entirely unknown.

Clinical context

Source · Editorial summary grounded in 5 cited references ↓

M75.90 sits at the bottom of the M75 specificity ladder. Use it only when the provider's documentation genuinely cannot support a more specific code — meaning neither the type of shoulder lesion (rotator cuff tear, impingement, bursitis, calcific tendinitis, adhesive capsulitis) nor the laterality (right or left) is recorded. In practice, this situation should be rare in an orthopedic setting: most encounters document at minimum which shoulder is involved, which would push you to M75.91 (right) or M75.92 (left) instead.

Before landing on M75.90, work through the M75 hierarchy. If the lesion type is known, use the specific subcategory: M75.0- (adhesive capsulitis), M75.1- (rotator cuff tear/rupture, non-traumatic), M75.2- (bicipital tendinitis), M75.3- (calcific tendinitis), M75.4- (impingement syndrome), M75.5- (bursitis), or M75.8- (other specified shoulder lesions). M75.90 is appropriate only after exhausting all of those options and confirming laterality is truly undocumented.

Note the Excludes2 instruction at the M75 category level: shoulder-hand syndrome (M89.0-) is coded separately and can be reported alongside M75.90 when both conditions exist. Traumatic shoulder injuries are coded with S-codes (S40–S49 range), not M75 codes — the distinction between traumatic onset and degenerative/non-traumatic pathology determines the correct code family. M75 codes do not use 7th-character extensions.

Sibling codes

Other billable codes under M75.9 (laterality / anatomic variants).

M75.92

Shoulder lesion, unspecified, left shoulder

M75.91

Shoulder lesion, unspecified, right shoulder

Frequently asked questions

Source · Generated from the editorial pipeline, verified against 5 cited references ↓

01When is M75.90 the correct code rather than a fallback?

M75.90 is correct only when the provider has not documented which shoulder is affected AND has not identified the type of shoulder lesion. Both elements must be unspecified simultaneously. This is genuinely rare in orthopedic practice.

02What is the difference between M75.90 and M75.80?

M75.80 is 'other shoulder lesions, unspecified shoulder' — used when the lesion is a known entity that simply doesn't fit any named M75 subcategory (adhesive capsulitis, rotator cuff tear, etc.) but exists as an identified finding. M75.90 is used when the lesion type itself is entirely uncharacterized. The distinction matters for specificity and payer scrutiny.

03Can M75.90 and a traumatic shoulder S-code appear on the same claim?

Generally no. M75 codes describe non-traumatic or degenerative shoulder lesions. If the shoulder condition is traumatic in origin, use the appropriate S-code (S40–S49 range) with the correct 7th-character extension (A = initial encounter, D = subsequent, S = sequela). Mixing M75.90 with a same-shoulder S-code for the same condition would be contradictory.

04Does M75.90 require a 7th character?

No. M-codes in the musculoskeletal chapter, including all M75 codes, do not use 7th-character extensions. Seventh-character extensions (A, D, S) apply to injury S-codes, not to M75.90.

05What documentation would allow me to move off M75.90 to a more specific code?

Document which shoulder is affected (right or left) — this immediately upgrades to M75.91 or M75.92. Then characterize the lesion: impingement (M75.4-), bursitis (M75.5-), rotator cuff tear (M75.1-), calcific tendinitis (M75.3-), or adhesive capsulitis (M75.0-). MRI, ultrasound, or arthroscopic findings typically provide enough detail to assign a specific subcategory code.

06Is M75.90 acceptable for an initial evaluation visit while awaiting imaging results?

It can be used temporarily if the provider genuinely cannot characterize the lesion at the time of the visit and laterality is undocumented. However, if the side is known at the initial visit (it almost always is), code M75.91 or M75.92 instead. Update the diagnosis code once imaging confirms the specific lesion type.

07What is the Excludes2 note at the M75 category level, and does it affect M75.90?

The M75 category carries an Excludes2 note for shoulder-hand syndrome (M89.0-), meaning shoulder-hand syndrome is not included in M75 codes but can be coded additionally when both conditions coexist. This note applies to all codes under M75, including M75.90.

Sources & references

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

Mira AI Scribe

Mira captures laterality, lesion type, onset mechanism (traumatic vs. non-traumatic), imaging results, and prior conservative care from the encounter note. When all of these elements are present, M75.90 is almost never the correct code — the scribe flags missing laterality or uncharacterized lesion type before submission, preventing audit exposure from chronic use of an unspecified catch-all code.

See how Mira captures M75.90 documentation