Closed treatment of an acromioclavicular joint dislocation performed without manipulating the separated bones back into position.

Verified May 8, 2026 · 8 sources ↓

Medicare: $276.56
Total RVUs: 8.28
Global, days: 90
Region: Shoulder

Drawn from CMSAAPCMdclarityFindacodeAAOS

Documentation requirements

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

Source · Editorial brief grounded in 8 cited references ↓

AC joint dislocation grade (Rockwood classification or equivalent) supported by imaging
Explicit statement that no manipulation or reduction was performed
Immobilization method applied (e.g., sling, shoulder immobilizer) and instructions given
Laterality — left or right AC joint — documented in the clinical note
Mechanism of injury and clinical exam findings supporting the diagnosis
Plan for follow-up and criteria for escalation to surgical management

Applicable modifiers

Modifiers commonly billed with this code.

Source · AMA CPT modifier descriptors · CMS NCCI Policy Manual

22 Increased complexity 24 Unrelated E/M during global 25 Significant separate E/M 50 Bilateral procedure 51 Multiple procedures 57 Decision for surgery 58 Staged or related 59 Distinct service 76 Repeat, same physician 77 Repeat, another physician 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 8 cited references ↓

CPT 23540 covers closed treatment of an acromioclavicular (AC) joint dislocation without manipulation. The physician evaluates and manages the injury — typically a Type I or Type II AC separation — using conservative measures such as sling immobilization, without attempting to reduce or reposition the clavicle relative to the acromion. No surgery is performed.

This code carries a 90-day global period. All routine follow-up visits, sling checks, and progress evaluations during that window are bundled. If you see the patient for an unrelated problem during those 90 days, append modifier 24 to the E/M. If the decision for surgery is made at a visit preceding a major procedure in the global, modifier 57 applies to that E/M.

Distinguish 23540 from 23545 (closed treatment with manipulation) and 23550/23552 (open treatment). Using 23540 when reduction was attempted or when stabilization hardware was placed will result in a down-coded or denied claim. Document the AC joint grade, the absence of manipulation, and the immobilization method applied.

RVU & reimbursement

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

Source · CMS Physician Fee Schedule, RVU26A · January 2026

Work RVU	2.3
Practice expense RVU	5.49
Malpractice RVU	0.49
Total RVU	8.28
Medicare national rate	$276.56
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	$276.56
HOPD (APC 5111) Hospital outpatient department	$252.01
ASC (PI A2) Ambulatory surgical center (freestanding)	$135.54

Common denial reasons

The recurring reasons claims for CPT 23540 get rejected.

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

Wrong code level — 23540 billed when manipulation or open reduction was documented, triggering downcoding or denial
Missing laterality — payers require LT or RT modifier; claims without it reject on edit
Unbundled E/M during the 90-day global without modifier 24 or 25, causing the office visit to deny
ICD-10 diagnosis code mismatch — AC dislocation diagnosis not present or coded as sprain rather than dislocation
Bilateral modifier 50 applied without clinical documentation supporting simultaneous bilateral AC dislocations

Frequently asked questions

Source · Generated from the editorial pipeline, verified against 8 cited references ↓

01When does 23540 apply versus 23545?

Use 23540 when the AC dislocation is treated conservatively with no attempt to reposition the joint — sling immobilization only. Use 23545 when closed manipulation is performed to reduce the separation. The operative or clinical note must explicitly address whether manipulation occurred; ambiguous notes default to the lower-level code on audit.

02Does the 90-day global period apply even for conservative sling treatment?

Yes. The 90-day global attaches to the procedure code regardless of treatment intensity. Routine follow-up visits, sling adjustments, and progress checks are all bundled. Bill an unrelated E/M during that window with modifier 24, or a significant separately identifiable same-day E/M with modifier 25.

03Is modifier 50 realistic for 23540?

Bilateral AC dislocations exist but are rare. If both AC joints are treated on the same date, append modifier 50 on a single claim line for professional billing. ASC billing requires separate LT and RT lines. Document bilateral injury explicitly — payers will scrutinize a bilateral claim for this code.

04What ICD-10 code pairs with 23540?

S43.10 (dislocation of AC joint, unspecified side), S43.11x (right), and S43.12x (left) are the primary diagnosis codes. Match laterality between the ICD-10 code and the LT/RT modifier. Coding AC separation as a sprain (S43.4xx) instead of a dislocation creates a CPT-ICD mismatch that many payers auto-deny.

05If the patient later needs open AC reconstruction during the global, which modifier applies?

Use modifier 58 if the escalation to open surgery was staged or anticipated. Use modifier 78 if the return to the OR was unplanned and the procedure is related to the original injury. Modifier 79 applies only to a truly unrelated procedure in the global window. Modifier 58 resets the global period clock; modifiers 78 and 79 do not.

06Can 23540 be billed in an ASC setting?

Yes. CMS assigns a separate ASC facility payment for 23540 — see the Site of Service comparison table on this page. ASC rates are lower than HOPD rates for this code. Confirm that your ASC's covered procedures list includes closed shoulder fracture/dislocation codes before scheduling.

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 AC joint grade, the explicit absence of manipulation, the immobilization device applied, and laterality directly from dictation. This prevents the two most common audit flags for 23540: notes that are silent on whether reduction was attempted (triggering a code-level challenge) and missing laterality that causes automatic claim rejection.

See how Mira captures CPT 23540 documentation