ICD code S42.134B – Nondisplaced coracoid process fracture, right shoulder, open

Key takeaways

S42.134B is a billable ICD-10-CM code for an open, nondisplaced fracture of the right coracoid process at the initial encounter.

The coracoid process belongs to the scapula, not the humerus, so this code sits in the S42.1 scapula subcategory.

The 7th character B covers active treatment of an open fracture only, and later visits move to D, G, K, P or S.

Documentation must name the coracoid process, the right side, nondisplaced alignment, and a wound that communicates with the fracture.

No CPT code names open treatment of the coracoid, so confirm with the payer whether 23585 or unlisted 23929 fits the procedure.

ICD-10 code S42.134B: Quick reference

ICD-10 code S42.134B describes a nondisplaced fracture of the coracoid process of the right shoulder, initial encounter for an open fracture. It is a billable code with no further subdivisions. In medical billing, payers match each character of the code against the clinical record. One wrong character is enough to deny the claim.

Verify the current code descriptor and tabular notes via the CDC/NCHS ICD-10-CM web tool, which publishes the official annual release.

What is a coracoid process fracture?

A coracoid process fracture is a break in the hook-shaped projection that curves forward from the top of the scapula. It sits just below the outer end of the clavicle and in front of the shoulder joint.

Several structures anchor to the coracoid. The pectoralis minor, the coracobrachialis and the short head of the biceps attach to it. So do the coracoclavicular, coracoacromial and coracohumeral ligaments.

Those attachments explain the two usual mechanisms. A direct blow to the front of the shoulder can break the process outright. A strong pull through the muscles or the coracoclavicular ligaments can avulse it, often alongside an acromioclavicular (AC) joint injury or a shoulder dislocation.

An open coracoid fracture is uncommon because the process lies deep beneath the deltoid and pectoralis major. A wound that reaches it usually means high-energy trauma, so expect other shoulder injuries in the same record. A nondisplaced fracture is often managed without surgery, but the open wound still needs urgent care.

What S42.134B means: Breaking down the code

Each character in S42.134B carries a distinct clinical meaning. Misreading any one of them produces a code that describes a different patient.

• S: Chapter 19 injury code (injury, poisoning and certain other consequences of external causes)
• 42: Fracture of shoulder and upper arm
• .1: Fracture of scapula (the shoulder blade)
• .13: Fracture of coracoid process
• .134: Nondisplaced fracture of coracoid process, right shoulder
• B: Initial encounter for open fracture (a wound communicates with the fracture site)

“Nondisplaced” means the fragments remain in anatomical alignment. The coder assigns it from the physician’s documented description, not from an independent reading of the imaging.

Two default rules in the S42 category apply here. A fracture not documented as displaced or nondisplaced is coded as displaced. A fracture not documented as open or closed is coded as closed. Either default moves the claim off S42.134B.

The 7th character B: When it applies and when it changes

The 7th character B designates an initial encounter for an open fracture. The patient is receiving active treatment, and the wound communicates with the fracture. Active treatment includes surgery, emergency care and evaluation by a new physician, and it ends when care moves to routine follow-up.

The most common error is continuing to bill S42.134B after active treatment ends. Once the provider documents routine follow-up, the 7th character changes to D, G, K or P, depending on the documented healing. Per the CMS ICD-10 coding guidelines, the character follows the nature of the encounter, not the date of the injury.

Sequela encounters use S42.134S, sequenced after the code for the late effect itself. If chronic shoulder pain is the reason for the visit, for example, report M25.511 (pain in right shoulder) first.

Open fracture classification and S42.134B

S42.134B records an open fracture without specifying its Gustilo-Anderson type. That system grades open fractures by wound size, contamination and soft-tissue damage, from Type I to Type IIIC. ICD-10-CM has no separate S42 codes for each type, so S42.134B applies to any documented open coracoid fracture.

The Gustilo type still matters operationally. Surgical teams and payers use it to judge the need for staged debridement and antibiotic cover. Capture it from the operative note in the supporting record, even though it does not change the diagnosis code.

S42.134B vs. adjacent codes: Choosing the right code

The coracoid process family, S42.13-, has six fifth- and sixth-character codes. Each takes seven 7th characters, so the family holds 42 billable codes. The table shows the initial open-fracture code for each one.

Three errors account for most wrong-code selections in this family:

• Closed instead of open: S42.134A is billed although the note describes a wound over the fracture.
• Wrong side: S42.135B is selected when the documented side is right.
• Wrong displacement: S42.131B is coded when the physician describes the fracture as nondisplaced.

One more mix-up deserves a check, because the shoulder has two bony prominences that sound alike. A nondisplaced open fracture of the greater tuberosity of the right humerus is S42.254B, not S42.134B. Confirm that the record names the coracoid before you submit. Cross-reference the AAPC ICD-10-CM code lookup for the descriptor text.

The five checks below follow the order a coder reads the record, and each one shows the code a failed check leads to.

Documentation requirements for ICD-10 code S42.134B

Every character in S42.134B must be supported in the clinical record. Coders cannot infer displacement from the fracture pattern or assume the side from the operative field. Submitting a clean claim for this code requires the following documentation:

1. Coracoid process named: The note must identify the coracoid process, not “scapula” or “shoulder” alone. An unspecified scapular site sends the code to the S42.10- range.
2. Explicit “nondisplaced” designation: The physician must state “nondisplaced” in the assessment, operative report or radiology interpretation. A record silent on displacement defaults to a displaced code.
3. Right laterality confirmed: The note must say “right shoulder” or “right coracoid”. A reference to the “dominant arm” is not enough without an explicit right or left.
4. Open fracture characterization: The wound must be documented as communicating with the fracture. “Laceration over the shoulder” alone may not be enough.
5. Initial, active-treatment encounter: The date of service must fall within active treatment for this fracture. “Initial” does not mean the first visit for any reason.
6. Imaging and associated injuries: X-ray or CT findings should support the nondisplaced description. Record any AC joint, clavicle or shoulder dislocation injury found on the same study.

Getting medical billing compliance right at the documentation stage keeps retroactive audits from turning into overpayment demands on paid claims.

CPT codes paired with ICD-10 code S42.134B

CPT has no procedure code that names the coracoid process. Scapular fracture treatment falls in the 23570-23585 range, and open-wound care uses the open-fracture debridement codes, starting at 11010. An open fracture does not automatically mean open treatment, so code the procedure the surgeon documents.

Apply the RT modifier to shoulder procedure codes where the payer requires it. Medicare and many commercial payers expect RT or LT on codes in the 23000 range. A missing modifier can trigger a CO-4 denial, so confirm each payer’s rule before submission.

External cause and associated injury codes for S42.134B

ICD-10-CM guideline Section I.C.20 encourages external cause codes with injury codes, though no national rule makes them mandatory. Many state reporting systems and payers do require them. For S42.134B, the external cause code records how the coracoid broke.

• V43.52XA: Car driver injured in collision with other type car in traffic accident, initial encounter — one example from the vehicle-crash range
• W50.0XXA: Accidental hit or strike by another person, initial encounter — for a direct blow to the front of the shoulder
• W19.XXXA: Unspecified fall, initial encounter — when the record documents a fall without further detail
• Y92 and Y93 codes: Y92 records the place of occurrence, and Y93 records the activity at the time of injury

External cause codes carry their own 7th character set, which has no open or closed distinction. A primary code ending in B therefore pairs with an external cause code that uses A for the initial encounter. Use the WHO ICD-10 browser to check the international hierarchy when confirming external cause categories.

Code associated injuries separately when the record documents them. An AC joint dislocation, a clavicle fracture or a shoulder dislocation each takes its own S42 or S43 code alongside S42.134B.

Common claim denial reasons for S42.134B and how to fix them

Six patterns account for most rejections on S42.134B claims. Strong denial management workflows catch them before submission. The table maps each pattern to its usual denial code and the fix.

Review denial explanations against the full list of medical billing denial codes to map each CO and OA adjustment reason code to its appeal route. Electronic remittance advice (ERA) shows which claim line carried the wrong 7th character.

How Pabau keeps S42.134B claims clean before they reach the payer

Most S42.134B denials start with a note that never stated the coracoid, the side or the open wound. The coder then has to chase the surgeon after the claim has already bounced.

Pabau, the practice management and billing platform we build, keeps the clinical note, the diagnosis code and the claim on one patient record. Its claims management software lets the coder see the documentation behind each code before submission. Claims then go out through Claim.MD, the US clearinghouse Pabau integrates with, which checks them against payer edits.

The result is fewer resubmissions for a code where one wrong character changes the bone, the side or the encounter.

Stop fracture claim denials before submission

Pabau keeps the fracture note, the diagnosis code and the claim in one patient record, and sends claims through Claim.MD for payer checks. See how orthopedic and injury practices use Pabau to cut claim rework.

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Conclusion

S42.134B only fits when four facts line up in the record. It needs the coracoid process, the right side, nondisplaced alignment and an open wound during active treatment. When any one of them is missing, ask for an addendum rather than coding around it.

The procedure side needs the same care. With no coracoid-specific CPT code, agree the open-treatment code with each payer before the first claim, not after a denial. Book a demo to see how Pabau helps orthopedic and injury practices submit fracture claims that pass on the first attempt.

Continue your research

Need to understand how claim denials are classified? Medical billing denial codes maps the most common CO and OA adjustment reason codes to their root causes and appeals pathways.

Working on building a cleaner claims submission process? Submitting a clean claim covers the documentation, coding, and payer-edit checks that reduce first-pass rejection rates.

Exploring how electronic remittance works after submission? Electronic remittance advice (ERA) explains how 835 transactions map denial codes back to specific claim lines.

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