ICD code S92.522A – Displaced fracture of middle phalanx of left lesser toe(s)

Key takeaways

S92.522A codes a displaced fracture of the middle phalanx of the left lesser toe(s), initial encounter for a closed fracture.

The code is left-specific, so a right-side injury is S92.521A and an undocumented side is S92.523A.

When the record does not say displaced or nondisplaced, ICD-10-CM defaults to displaced, and the nondisplaced left-side code is S92.525A.

An open fracture of the same bone takes 7th character B (S92.522B), and a proximal phalanx fracture belongs in S92.51-.

Pabau, the practice management platform we build, connects to the Claim.MD clearinghouse, so US practices can send claims with the correct ICD-10 and CPT pairing.

ICD-10 Code S92.522A: Full descriptor and anatomical context

ICD-10 Code S92.522A is the billable code for a displaced fracture of the middle phalanx of the left lesser toe(s), initial encounter for closed fracture. Each part of that descriptor narrows the choice, so accurate medical billing workflows start with the anatomy, the side, and the fracture type.

Each lesser toe has three phalanges: proximal, middle, and distal. The great toe has only two, which is why its fractures sit in the separate S92.4- subcategory. A fracture of the proximal phalanx of a lesser toe is coded in S92.51-, not S92.52-.

Middle phalanx fractures usually follow direct trauma, such as a dropped object, a stubbing injury, or a crush. They are commonly managed in podiatry, emergency medicine, and orthopedic settings.

Code hierarchy: Where S92.522A sits in ICD-10-CM

S92.522A belongs to Chapter 19 of the ICD-10-CM tabular list (Injury, poisoning and certain other consequences of external causes). Per the CMS ICD-10 codes page and the official tabular, the full path is:

• S00-T88: Injury, poisoning and certain other consequences of external causes
• S90-S99: Injuries to the ankle and foot
• S92: Fracture of foot and toe, except ankle
• S92.5-: Fracture of lesser toe(s)
• S92.52-: Fracture of middle phalanx of lesser toe(s)
• S92.522: Displaced fracture of middle phalanx of left lesser toe(s)
• S92.522A: Displaced fracture of middle phalanx of left lesser toe(s), initial encounter for closed fracture

The S92 category covers open and closed fractures alike, and the 7th character tells them apart. An open fracture of the same bone, with a wound that exposes it, is coded S92.522B. The tabular also says a fracture not documented as open or closed is coded as closed.

Understanding the 7th character for S92.522

The 7th character in S92.522A is a frequent source of coder error. Under the ICD-10-CM Official Guidelines for Coding and Reporting, “initial encounter” means the patient is receiving active treatment. It does not mean the patient’s literal first visit.

A specialist who sees a patient referred from the emergency department is still providing active treatment, so the code keeps its initial encounter character. Move to D only when active treatment has ended and the provider is monitoring healing.

Displaced vs. nondisplaced fracture: Choosing the correct code

A displaced fracture means the bone ends have moved out of their normal position. A nondisplaced fracture means the bone has cracked but the fragments stay aligned. For the left middle phalanx, that distinction decides between S92.522A and S92.525A.

ICD-10-CM guideline I.C.19.c and the S92 tabular note both say a fracture not documented as displaced or nondisplaced is coded as displaced. That makes S92.522A the default for an unspecified left middle phalanx fracture. Still, query the clinician when the imaging report and the note disagree.

Adjacent and commonly confused codes

Most errors with S92.522A come from picking the wrong side, the wrong displacement status, or the wrong bone. The siblings below differ from S92.522A by a single element.

Assigning S92.521A to a left-foot injury, or S92.523A when the note names the left side, creates a mismatch with the clinical record. Payers that audit against documentation will deny it. The decision path below runs the five checks in the order a coder meets them in the note.

Documentation requirements for S92.522A

Missing documentation is a common cause of claim denial for fracture codes. The clinical note should support every element of the descriptor before S92.522A is assigned.

• Side: The note must state that the left foot is injured. Without it, the code drops to S92.523A.
• Bone and toe: The note should name the middle phalanx and which lesser toe (second, third, fourth, or fifth) is fractured.
• Displacement: Imaging or the clinician’s note should describe displacement. If it says “nondisplaced,” the code is S92.525A.
• Closed or open: State whether the skin over the fracture is intact. An open fracture is S92.522B.
• Mechanism of injury: Record how the injury happened, such as a dropped object or a stubbed toe. This supports any external cause codes reported.
• Treatment plan: State whether the approach is buddy taping, closed reduction, or open treatment. The treatment decides which CPT code pairs with S92.522A.
• Active treatment: Show that the provider is actively treating the fracture, which supports the 7th character A.

Building these elements into the visit template means the coder finds side, bone, displacement, and skin status in one place before the claim goes out.

Inclusions, exclusions, and instructional notes

S92.522A carries no notes of its own, but it inherits instructions from the levels above it. Per the CDC/NCHS ICD-10-CM tool, these apply:

• Chapter 19 note: Use secondary codes from Chapter 20, External causes of morbidity, to indicate the cause of injury.
• Chapter 19 use additional code: Identify any retained foreign body, if applicable (Z18.-).
• S92 note: A fracture not indicated as displaced or nondisplaced is coded to displaced. A fracture not indicated as open or closed is coded to closed.
• S92 Excludes2: Fracture of ankle (S82.-), fracture of malleolus (S82.-), and traumatic amputation of ankle and foot (S98.-).
• S92.5 Excludes2: Physeal fracture of phalanx of toe (S99.2-), the growth plate injury seen in children.

Typical external cause codes include W22.8XXA for striking against or being struck by other objects. Place of occurrence comes from Y92 and activity from Y93. National guidelines do not mandate external cause reporting, but many states and payers require it. Missing codes are a frequent finding in denial management in healthcare.

Paired CPT procedure codes for lesser toe fracture encounters

S92.522A is a diagnosis code only, so the claim also needs a matching CPT code describing the procedure. Lesser toe fractures use the 28510 to 28525 range, while 28490 to 28505 are reserved for the great toe. Confirm pairings against the current AMA CPT codebook, as coverage rules vary by payer.

Payers check that the CPT code and the diagnosis code are clinically consistent. Billing CPT 28525 against a note that only documents buddy taping will draw a medical necessity denial. Practices that submit through the Claim.MD clearinghouse can catch CPT-to-ICD-10 mismatches before the claim reaches the payer.

Common claim denial reasons and how to avoid them

Displaced middle phalanx fracture claims carry a handful of predictable denial triggers. Fixing each one before submission costs far less than an appeal. The clean claim submission standard expects every required element to be present at billing.

• Wrong side: Coding S92.522A when the note documents the right foot (S92.521A), or when no side is recorded (S92.523A).
• Wrong 7th character: Using D while active treatment continues, or using A once treatment has ended. Coding A for an open fracture that needs B is the same error.
• Displacement mismatch: Assigning S92.522A when the imaging report says “nondisplaced.” That fracture is S92.525A.
• Wrong bone: Using S92.52- for a proximal phalanx fracture (S92.51-) or for the great toe (S92.4-).
• CPT linkage failure: Billing a great-toe CPT code (28490 to 28505) for a lesser toe, or open treatment (28525) against a note describing conservative care.
• Missing external cause code: Leaving out a Chapter 20 code where the state or payer requires one.

Payer requirements and prior authorization

Medicare and most commercial payers expect medical necessity documentation to support claims coded with S92.522A. Requirements vary by payer and plan year, so verify current local coverage determinations before billing. Common expectations include:

• Imaging evidence on file: An X-ray or CT confirming the fracture should be available for records review. Imaging ordered but not yet resulted does not support the claim.
• Appropriate CPT pairing: The procedure code must reflect what the clinical note documents. Medicare’s Claims Processing Manual (CMS Pub. 100-04) sets the rules for diagnosis and procedure reporting.
• Prior authorization: Closed treatment (CPT 28510 or 28515) rarely needs prior authorization. Open treatment (CPT 28525) may, so verify with the plan before scheduling surgery.

The AAPC ICD-10-CM code reference is a useful secondary resource for checking code validity and payer billing notes.

How Pabau supports accurate toe fracture claims

Many podiatry practices still code fractures from free-text notes, then key the claim into a separate billing portal. Side, bone, and displacement details get lost between the two, and the denial arrives weeks later.

Pabau keeps the treatment note, the diagnosis code, and the invoice on the same patient record. Its error-catching claims software sends US claims through the Claim.MD clearinghouse, which checks each claim before it reaches the payer. The coder reads side, bone, and displacement from the note that sits beside the claim.

The outcome is fewer side and displacement errors leaving the practice, and less time spent reworking rejected fracture claims.

Reduce coding errors before they reach the payer

Pabau keeps notes, diagnosis codes, and invoices on one patient record and integrates with the Claim.MD clearinghouse for US claims. That helps podiatry practices send fracture claims with the right ICD-10 and CPT pairing.

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Conclusion

S92.522A is only correct when four facts line up: left side, middle phalanx of a lesser toe, displaced (or undocumented), and closed. Change any one and the code changes with it, to S92.521A, S92.525A, S92.51-, or S92.522B.

The practical step is to make the note capture those four facts at the visit, rather than leaving the coder to infer them. Pair that with a lesser-toe CPT code that matches the documented treatment, and these claims should clear on the first pass.

Pabau keeps the note and the claim on one record and sends US claims through its Claim.MD clearinghouse integration. Book a demo to see how Pabau helps your practice submit cleaner fracture claims.

Continue your research

Need to understand denial codes and how to respond? Denial codes in medical billing covers the most common CARC codes and corrective action steps.

Want to understand how clean claims are built? Medical billing compliance explains the documentation and coding standards that keep claims out of the denial queue.

Submitting claims electronically through a clearinghouse? Claim.MD clearinghouse explains how Pabau’s US clearinghouse integration routes and validates claims before they reach the payer.

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