ICD-10 code S52.529D: Torus fracture of lower end of unspecified radius

Key takeaways

ICD-10 code S52.529D describes a torus fracture of the lower end of the unspecified radius, subsequent encounter for fracture with routine healing.

S52.529D is a billable ICD-10-CM code valid for HIPAA-covered transactions in the FY2026 edition, effective October 1, 2025.

The 7th character D separates this code from S52.529A (initial encounter) and S52.529G (delayed healing). Picking the wrong character is a common cause of claim denial.

Radius codes sit in the S52.5- family and ulna codes in S52.6-, so S52.529D and S52.629D describe two different bones.

Practice management software like Pabau helps orthopedic and physical therapy practices submit the correct encounter-type code at every follow-up visit.

ICD-10 code S52.529D covers a torus fracture of the lower end of the unspecified radius, subsequent encounter for fracture with routine healing. It applies once active treatment is finished and the physician documents healing without complication.

The code is billable and valid for reimbursement under HIPAA-covered transactions. The FY2026 edition took effect on October 1, 2025, and remains current for FY2026 claims. It appears in the CMS ICD-10-CM code files maintained by the Centers for Medicare and Medicaid Services.

Two characters do most of the damage on these claims. Coding S52.529A at a six-week cast check is the classic denial. Swapping S52.5- for S52.6- moves the diagnosis from the radius to the ulna. This article covers the 7th character table, the documentation that supports D, and the related codes.

What a torus fracture of the distal radius means

A torus fracture, also called a buckle fracture, is an incomplete fracture in which the bone cortex buckles on the compression side. There is no complete break in continuity. The bone crumples inward under axial load rather than cracking through.

That separates it from two neighbors. A greenstick fracture bends the bone and breaks one cortex. A complete fracture disrupts both cortices. S52.389A covers a bent bone of the radius, where the shaft deforms without a visible cortical break.

The anatomical site in S52.529D is the lower end of the radius, the distal portion nearest the wrist. “Unspecified” laterality means the medical record does not state whether the fracture sits on the right or left side.

It also covers records where laterality cannot be determined from the documentation. Always try to confirm the side before defaulting to the unspecified code. Where laterality is documented, use S52.521D for the right radius or S52.522D for the left.

• Torus fracture: Incomplete fracture with cortical buckling on the compression side
• Lower end of radius: The distal radius, the wrist-adjacent segment of the bone
• Unspecified laterality: Used only when the record does not confirm right or left
• Subsequent encounter: The patient is past active treatment and receiving routine follow-up care
• Routine healing: No documented complications such as delayed union, nonunion, or malunion

Bone family comes before the 7th character. Distal radius fractures live in S52.5- and distal ulna fractures in S52.6-. The pair S52.529D and S52.629D trips up experienced coders, and only the radiology report settles which bone buckled.

The ulna side of the family runs wide, and S52.692R sits at the same anatomical level. Physical therapy documentation for pediatric orthopedic follow-up depends on that distinction as much as on the encounter type.

The 7th character options for S52.529

The 7th character is the single most important coding decision for the S52.529 family. It turns the base code into a specific, billable encounter type. Submitting A when the patient is returning for follow-up drives a large share of orthopedic fracture denials.

Encounter-type qualifiers are a core component of injury coding in the WHO ICD-10 classification system on which ICD-10-CM is based. The CDC/NCHS ICD-10-CM web tool lists all valid 7th characters for S52.529.

Torus fractures are closed injuries by definition, so the open-fracture 7th characters used elsewhere in S52 do not apply. A, D, G, K, P, and S are the only valid options for S52.529.

ICD-10 code S52.529D matches the D row above, where active treatment is complete and healing is documented without complication. If the follow-up radiograph shows delayed union, switch to S52.529G. The same qualifier works the same way across the S-chapter, and S53.442D applies it to an elbow sprain at follow-up.

When to use S52.529D vs other S52.529 codes

The decision tree for ICD-10 code S52.529D comes down to two questions. Is this a subsequent encounter rather than the first active treatment visit? And is healing progressing routinely, with no delayed union, nonunion, or malunion documented?

• Use S52.529A when the patient presents for the first active management of the fracture. That covers the initial cast application, the ED visit, or the first orthopedic office visit where treatment begins.
• Use ICD-10 code S52.529D when active treatment is complete and the patient is in a routine monitoring phase. This is the code for the second, third, and later cast checks, assuming the record supports normal healing.
• Use S52.529G when the physician documents delayed healing at a follow-up visit. The note should record the expected healing timeline against the actual one.
• Use S52.529K when imaging confirms nonunion. This code fits fractures that have failed to heal biologically, which often require surgical intervention. S52.209K carries the same qualifier on an ulna shaft fracture.
• Use S52.529P when the fracture has united in an abnormal position. The physician’s note should describe the malunion and any functional consequences.
• Use S52.529S for late effects, such as chronic wrist stiffness that persists after the fracture itself has resolved.

Documentation wording decides the character. A patient six weeks post-casting whose physician writes “fracture healing well, no concerns” supports ICD-10 code S52.529D. A note reading “healing appears delayed on X-ray, return in four weeks” shifts the code to S52.529G. The physician’s documented assessment drives the 7th character, not the visit number.

Coding guidelines and documentation requirements

The ICD-10-CM Official Guidelines for Coding and Reporting (Section I.C.19.a) carry the authoritative rules for fracture encounter coding. CMS and the NCHS maintain them jointly. The guidelines define a subsequent encounter as one that occurs after active treatment of the condition is complete.

Active treatment covers the initial encounter and any visit where surgical or non-surgical management of the fracture is performed. Once care becomes monitoring and routine review, subsequent encounter coding applies. The AAPC ICD-10-CM code reference carries additional coding notes on the S52 category.

Practices that use claims management software can flag S52.529A submissions automatically and prompt coders to check whether a subsequent encounter code applies. That cuts the manual review burden on billing staff, which matters most in high-volume orthopedic and urgent care settings. Accurate clinical documentation in the patient record is what supports the D qualifier at audit.

Documentation checklist for S52.529D

• Confirm this is not the first visit where active treatment was initiated, whether by casting, splinting, reduction, or surgery
• Physician note documents that healing is progressing normally
• No documentation of delayed union, nonunion, or malunion at this visit
• Injured bone confirmed as the radius, not the ulna, which would move the code to the S52.6- family
• Anatomical site confirmed as the lower end of the radius, near the wrist
• Laterality is unspecified in the record or cannot be determined, otherwise use S52.521D or S52.522D
• Fracture type confirmed as torus or buckle, since a complete fracture falls under a different S52.5- subcategory

Physical therapists managing post-fracture rehabilitation also use subsequent encounter codes once the physician hands off routine care. The treating provider’s documentation governs the encounter type, whichever discipline sees the patient that day. A medical coding cheat sheet keeps those rules in front of the billing team.

ICD-10-CM code hierarchy for S52.529D

Knowing where S52.529D sits in the ICD-10-CM hierarchy helps coders navigate the tabular list and find parent and sibling codes quickly. The structure follows a consistent parent-to-child relationship, from chapter level down to the specific billable code.

• Chapter: S00-T88 – Injury, poisoning and certain other consequences of external causes
• Section: S50-S59 – Injuries to the elbow and forearm
• Category: S52 – Fracture of forearm
• Subcategory: S52.5 – Fracture of lower end of radius
• Subcategory: S52.52 – Torus fracture of lower end of radius
• Code: S52.529 – Torus fracture of lower end of unspecified radius
• Billable code: S52.529D – Subsequent encounter for fracture with routine healing

The parent code S52.529 is not valid for submission without a 7th character. ICD-10-CM requires the full seven-character code for injury codes in this chapter. Submitting S52.529 on its own will be rejected at the clearinghouse.

Sibling codes in the neighboring subcategories follow the same pattern. S52.514M sits in S52.51, at the radial styloid process. Specificity to the 7th character is mandatory across all of them.

Clinical context: Torus fractures in practice

Torus fractures of the distal radius are among the most common pediatric fractures in emergency departments and urgent care. They occur predominantly in children aged 5 to 10, when bone density and periosteal thickness let axial loading buckle the cortex rather than break it.

A fall on an outstretched hand is the classic mechanism. The child typically reports wrist pain and tenderness over the distal radius, without gross deformity.

Treatment is usually conservative. The child wears a short-arm cast or removable splint for three to four weeks, then returns for clinical and radiographic review. Because the fracture is incomplete and the periosteum stays intact, healing is generally predictable.

That is why D is the most common 7th character for this fracture type at follow-up. Delayed union and nonunion are rare, but each warrants its own 7th character when documented. Sports medicine practices see this pattern often in younger athletes.

The same mechanism can buckle the distal ulna, and some children buckle both bones in one fall. Where the radiology report describes an isolated ulnar buckle, the code moves to the S52.6- family. Where both bones are involved, code each fracture separately with its own 7th character.

Related ICD-10-CM codes for torus fracture of the distal radius

Accurate fracture coding often means knowing which adjacent codes to consider. The table below covers the most frequently used codes in the S52.529 family and the wider S52 category.

Sequela coding follows the same logic outside the fracture categories. S56.529S applies the S qualifier to a forearm extensor muscle laceration. The qualifier describes the residual effect rather than the original injury encounter.

Common coding mistakes with S52.529D

Five errors account for most denials and audit findings on this code. Each one is preventable with a documentation check before submission.

• Coding the wrong forearm bone. S52.529D is a radius code and S52.629D is an ulna code. The two differ by one digit, so read the radiology report rather than the visit summary.
• Defaulting to the A character at every visit. Once active treatment is complete, follow-up visits take D. Reusing A is the single largest source of denials on fracture aftercare claims.
• Using the unspecified code when the chart names a side. Payers increasingly reject unspecified laterality where documentation supports right or left.
• Submitting S52.529 without a 7th character. Six-character injury codes fail edits at the clearinghouse before the payer ever sees them.
• Using D after the fracture has fully healed. Once healing is complete and only residual symptoms remain, the correct code is the sequela code S52.529S.

How Pabau keeps fracture follow-up coding accurate

In most orthopedic and therapy practices, encounter-type coding is a memory task. A coder opens the chart, reads a short follow-up note, and picks a 7th character from recall. Nothing in the workflow connects this visit to the fracture episode that started weeks earlier, so the initial encounter code gets carried forward by habit.

Practice management software like Pabau links every follow-up appointment back to the original injury record. Your team can see at a glance that active treatment closed at the first cast application. A routine cast check then gets the D character instead of the A character.

Structured note templates also prompt the physician to state healing status in words that hold up at audit. Our claims management software then checks the coded claim before it leaves the practice. It flags an encounter-type mismatch while the fix is still cheap.

The outcome is fewer denials on aftercare visits and less rework for your billing team. You also get paid faster on the follow-up appointments that fill an orthopedic schedule.

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Pabau's claims management tools help orthopedic and physical therapy practices apply the correct encounter-type qualifier every time, cutting claim denials on subsequent fracture visits.

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Conclusion

Fracture follow-up coding is one of the highest-risk areas for denial in orthopedic and urgent care billing. With ICD-10 code S52.529D, two details carry the risk. The first is the bone. The radius sits in S52.5-, and the ulna in S52.6-.

The second is the 7th character, where defaulting to A at every visit generates preventable rejections. Getting both right takes clear physician documentation at each follow-up and a billing workflow that verifies encounter type before submission.

Confirm the bone from the imaging report, confirm laterality from the chart, and confirm healing status from the physician’s own words. Pabau’s claims management tools catch encounter-type mismatches before claims leave the practice. To see how that works in a live orthopedic workflow, book a demo.

Continue your research

Coding an ulna fracture that healed out of position? S52.266R covers a nondisplaced ulna shaft fracture with malunion at a subsequent encounter.

Need the code for a forearm fracture-dislocation? S52.271A walks through Monteggia’s fracture of the right ulna at the initial encounter.

Billing the cast that started the fracture episode? A4580 explains how plaster cast supplies are billed alongside the diagnosis code.

Handing a patient rehab work after cast removal? Home exercise program gives you a template to document and share the plan.

Coding a wrist fracture that united in the wrong position? S62.163P covers a displaced pisiform fracture with malunion.

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