Open partial removal of the distal clavicle, typically performed to relieve AC joint pain from arthritis or arthrosis — the open-approach counterpart to arthroscopic code 29824.

Verified May 8, 2026 · 6 sources ↓

Medicare: $564.81
Total RVUs: 16.91
Global, days: 90
Region: Shoulder

Drawn from AAPCCMSAAOS

Documentation requirements

What must appear in the operative or office note to support the claim.

Source · Editorial brief grounded in 6 cited references ↓

Confirm and document open surgical approach — a scope-based distal claviculectomy routes to 29824, not 23120
Record the measured size of bone resected; payers and auditors flag operative notes without explicit excision dimensions
Specify the clinical indication (e.g., AC joint osteoarthritis, arthrosis) with a matching ICD-10 diagnosis code
If billing with a concurrent shoulder procedure, document distinct site of entry for the claviculectomy to support modifier 59
Note laterality (left vs. right shoulder) in both the operative report and the claim to support LT/RT modifiers
Include pre-operative conservative treatment history to establish medical necessity for surgical intervention

Applicable modifiers

Modifiers commonly billed with this code.

Source · AMA CPT modifier descriptors · CMS NCCI Policy Manual

22 Increased complexity 50 Bilateral procedure 51 Multiple procedures 59 Distinct service 62 Co-surgeons 78 Unplanned return — related 79 Unrelated during global 80 Assistant surgeon LT Left side RT Right side

What this code covers

Source · Editorial summary grounded in 6 cited references ↓

CPT 23120 covers open partial claviculectomy — most commonly distal clavicle resection at the acromioclavicular joint to eliminate pain from osteoarthritis or chronic arthrosis. This is the open version of the Mumford procedure; if the surgeon uses a scope, bill 29824 instead. The operative incision must be at least approximately two inches, and the resection must constitute actual bone removal, not mere osteophyte shaving. Some payers consider excisions under 1 cm inclusive to the primary shoulder procedure, so verify carrier policy before appending modifier 59 to report 23120 separately alongside arthroscopic codes.

The 90-day global period covers the day-before visit, the surgery itself, and all routine post-op care through day 90. Anything unrelated to the claviculectomy billed in that window needs modifier 24 (E/M) or 79 (unrelated procedure). When 23120 is performed alongside acromioplasty or rotator cuff repair, AAOS guidance supports separate reporting if a distinct surgical site entry is documented — but modifier 59 is required and will draw scrutiny from payers and NCCI edits. Always confirm bundling against the AAOS Complete Global Service Data and current NCCI tables before billing both.

Side laterality matters: append LT or RT for unilateral procedures. Bilateral partial claviculectomy — uncommon but possible — requires modifier 50. When two surgeons each perform distinct components of the procedure, modifier 62 applies. Document the excision size explicitly in the operative note; vague language like 'distal clavicle resected' without a measurement is a common audit flag.

RVU & reimbursement

Component RVUs and Medicare national rate. Actual payment varies by GPCI locality.

Source · CMS Physician Fee Schedule, RVU26A · January 2026

Work RVU	7.21
Practice expense RVU	8.22
Malpractice RVU	1.48
Total RVU	16.91
Medicare national rate	$564.81
Global period	90 days

Payment by site of service

Medicare pays different rates by setting. HOPD typically pays substantially more than ASC for the same procedure.

Source · CMS OPPS Addendum B·ASC HCPCS payment rates·2026

Setting	Medicare rate (national)
Office (PFS non-facility) Procedure performed in physician's office	$564.81
HOPD (APC 5113) Hospital outpatient department	$3,342.87
ASC (PI A2) Ambulatory surgical center (freestanding)	$1,644.87

Common denial reasons

The recurring reasons claims for CPT 23120 get rejected.

Source · Editorial brief grounded in CMS NCCI edits, AAOS coding appeals, and cited references ↓

Wrong code selected — arthroscopic distal claviculectomy (Mumford) billed as 23120 instead of 29824
Bundling denial when 23120 is billed same-day with a primary shoulder arthroscopy code without modifier 59 and documented distinct site entry
Carrier determines excision was less than 1 cm and considers it incidental to the primary shoulder procedure
Missing or mismatched laterality — LT/RT modifier absent when payer requires it for unilateral procedures
Insufficient medical necessity documentation — no prior conservative treatment noted to justify surgical resection

Frequently asked questions

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

01What is the difference between CPT 23120 and 29824?

23120 is the open partial claviculectomy. 29824 is the arthroscopic distal claviculectomy (Mumford procedure). Approach determines the code — you cannot bill 23120 for a scope-based resection.

02Can 23120 be billed with rotator cuff repair on the same day?

Yes, but it requires modifier 59 and a documented distinct surgical site entry for the claviculectomy. Without that documentation, payers will bundle it into the primary procedure. Verify against current NCCI edits and your carrier's bundling policy before billing both.

03How much bone needs to be removed to justify 23120?

More than simple osteophyte shaving — actual resection of a portion of the distal clavicle is required. Some carriers treat excisions under 1 cm as incidental to the primary shoulder procedure. Document the excision size in centimeters every time.

04Does 23120 carry a global period, and what does that cover?

Yes — 23120 has a 90-day global period. It covers the day-before visit, the operative session, and all routine post-op care through day 90. Unrelated E/M visits in that window need modifier 24; unrelated procedures need modifier 79.

05Is bilateral partial claviculectomy coded with modifier 50?

Yes. If both distal clavicles are resected in the same session, append modifier 50. For a single side, use LT or RT. Bilateral claviculectomy is rare — confirm the operative report documents bilateral pathology and bilateral resection explicitly.

06When would modifier 22 apply to CPT 23120?

Modifier 22 is appropriate when the procedure is substantially more complex than typical — for example, severe deformity, prior hardware at the AC joint, or significant scarring requiring unusual additional work. Attach a cover letter with the claim explaining the increased complexity and extra time documented in the operative report.

Sources & references

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

Mira AI Scribe

Mira's AI scribe captures the surgical approach (open vs. arthroscopic), the measured amount of distal clavicle resected, the documented AC joint pathology driving the procedure, and any concurrent shoulder procedures performed through separate incision sites. This prevents the most common denial scenario: a vague operative note that gives payers grounds to downcode to incidental bone shaving or bundle the claviculectomy into the primary shoulder procedure.

See how Mira captures CPT 23120 documentation