ICD-10 Code S52.002F: left ulna open fracture, routine healing

Key takeaways

S52.002F is a billable ICD-10-CM code for an unspecified fracture of the upper end of the left ulna. The 7th character F adds: subsequent encounter for open fracture type IIIA, IIIB, or IIIC with routine healing.

The 7th character F marks a follow-up visit for a Gustilo type III open fracture that is healing normally. It is not a closed fracture, and it is not a healing complication.

Documentation must confirm laterality (left), fracture site (proximal ulna), the documented Gustilo grade, and that healing is progressing on schedule.

Practice management software like Pabau validates patient and insurance details, then submits fracture follow-up claims and tracks their status through integrated clearinghouses.

ICD-10 Code S52.002F is a billable code for a follow-up visit on an unspecified fracture of the upper end of the left ulna. The 7th character F carries two facts at once. The fracture was open at Gustilo type IIIA, IIIB, or IIIC, and it is now healing routinely. Coders who read F as a healing complication pick the wrong code. Delayed healing on a closed fracture is S52.002G.

This reference covers the full code description, every valid 7th character for S52.002, and the Gustilo grading that drives the choice. It then works through documentation requirements, common coding errors, sibling codes, and the CPT codes paired with this diagnosis.

ICD-10 Code S52.002F: quick reference

The table below gives coders a fast lookup for ICD-10 Code S52.002F before the full breakdown.

What is S52.002F?

S52.002F is a billable ICD-10-CM code for a follow-up visit after a high-grade open fracture of the proximal left ulna. The patient is past active treatment, the wound was graded Gustilo type III at presentation, and the bone is knitting on schedule. Each element of the description carries a separate coding implication.

• Unspecified fracture: The fracture type (displaced or non-displaced) is not documented in the clinical record. When physician notes do not specify displacement, ICD-10-CM guidelines direct coders to the "unspecified" subcategory. This is not an error. It reflects the documentation as written.
• Upper end of ulna: Anatomically, the upper end of the ulna is the proximal end, encompassing the olecranon process and the coronoid process. Coders sometimes confuse "upper end" with "shaft" fractures. Proximal ulna fractures belong under S52.0.
• Left ulna: Laterality is required at the most specific code level. Using a right-ulna code (S52.001F) or an unspecified-laterality code for a documented left-sided injury is a coding error under CMS ICD-10-CM guidelines.
• Subsequent encounter: The patient is no longer in the active treatment phase. They are receiving routine aftercare while the fracture heals.
• Open fracture type IIIA, IIIB, or IIIC: The original injury broke the skin and was graded type III on the Gustilo scale. That means extensive soft-tissue damage, and in type IIIC an arterial injury that requires repair. The grade is set by the initial injury record, not by today’s exam.
• Routine healing: At this encounter the physician documents healing that is progressing as expected. Nothing in the note describes delayed union, nonunion, or malunion.

The CDC/NCHS ICD-10-CM tool confirms S52.002F as an active, billable code. Check the official tabular list before each new fiscal year, since the annual update cycle can revise a description without retiring the code.

The 7th character F: open type III with routine healing

The 7th character is the most consequential coding decision on any S52.002 claim. It is easy to read it as a single fact, but it encodes two. The first is the fracture type at presentation: closed, open type I or II, or open type IIIA, IIIB, or IIIC. The second is the healing status at this encounter: routine, delayed, nonunion, or malunion. Sixteen characters cover every combination, and F sits at the intersection of open type III and routine healing.

Notice what the set does not contain. There is no character for delayed healing on its own, because every subsequent-encounter character names a fracture type as well. That is why F cannot mean delayed healing. Delayed healing lives in G, H, and J, split by fracture type, and routine healing lives in D, E, and F on the same pattern.

• F vs. D: Both describe routine healing at a follow-up visit. D is for a closed fracture and F is for a Gustilo type III open fracture. The deciding evidence is the wound status recorded at the original injury.
• F vs. E: Both cover open fractures healing routinely, and the split is the Gustilo grade.
• F vs. J: Both cover Gustilo type III fractures. The split is whether the treating physician documents healing as routine or delayed.

Gustilo classification: what makes an open fracture type IIIA, IIIB, or IIIC

ICD-10-CM ties the open-fracture 7th characters directly to the Gustilo-Anderson classification. The scale grades the wound and the surrounding soft tissue, not the bone. A coder does not assign the grade. The surgeon does, and the coder reads it out of the record.

ICD-10-CM collapses IIIA, IIIB, and IIIC into one character, so a coder never has to separate the three subtypes. Telling type III apart from type I or II does matter, and it decides whether the routine-healing follow-up is coded F or E.

S52.002F in the ICD-10-CM code hierarchy

Knowing where S52.002F sits in the ICD-10-CM structure helps coders reach the correct parent code and cross-reference its exclusion notes. The WHO ICD-10 browser provides the international classification framework. The US ICD-10-CM system adapts that structure with the extra granularity that laterality and 7th characters require.

S52.002 itself is not billable. A 7th character is always required before the code can go on a claim. Submitting S52.002 without the character appended will trigger a claim edit as an invalid code.

Documentation requirements at a follow-up visit

The open-fracture half of this code is where documentation most often falls short. Payers reviewing an S52.002F claim look for the Gustilo grade and the wound status. Neither one can be inferred from a follow-up exam, so both have to be carried forward from the original injury record.

• Laterality (left): The note must clearly identify the left side. Ambiguous language such as "the ulna" or "the affected arm" is insufficient when ICD-10-CM requires laterality specificity.
• Fracture site (upper end/proximal ulna): The note must place the fracture at the proximal ulna. References to the olecranon or the coronoid process support the upper end classification. Shaft references do not.
• Encounter type (subsequent): The encounter must be a follow-up visit, not the first treatment contact. The note should reflect aftercare such as wound checks, cast or splint changes, imaging review, or a physical therapy referral.
• Open fracture with a documented Gustilo type III grade: This is the element that separates F from every other routine-healing character. The initial injury record must state that the fracture was open and grade it IIIA, IIIB, or IIIC. Carry that grade forward into the follow-up note so the claim stands on its own.
• Wound and soft-tissue status at this visit: Describe the wound as it is now. Note closure, graft or flap status, drainage, and any signs of infection. This supports both the open-fracture character and any wound care billed alongside the visit.
• Evidence of routine healing: The note must show healing on the expected timeline. Language such as "callus formation appropriate for six weeks post-injury" or "alignment maintained on repeat imaging" supports routine healing. A note describing delayed union, nonunion, or malunion moves the code to J, N, or R.
• Fracture type (unspecified): If the original fracture type is not documented, unspecified is appropriate. If later imaging clarifies displacement, move to the more specific code. Coders should not assume displacement or non-displacement without documentation.

Review the clean claim submission requirements that apply to injury diagnosis codes. Then make sure the open-fracture grade and the healing assessment appear in the assessment or plan section, not only in the history.

Per AAPC ICD-10-CM coding guidance, the fracture type and the healing assessment must both come from the treating physician. A coder cannot upgrade an open fracture to type III because the wound looks severe in a photograph. Nor can a coder call healing routine simply because no complication was mentioned.

Common coding errors with S52.002F

Most S52.002F denials are preventable. The errors below account for the majority of rejections on proximal ulna fracture follow-up visits.

• Reading F as delayed healing: This is the most common error on this code, and it comes from memorizing a partial extension list. F means open type III with routine healing. Delayed healing is G for a closed fracture, H for open type I or II, and J for open type III.
• Using F on a closed fracture: If the record describes intact skin at presentation, the routine-healing follow-up is S52.002D. F asserts an open wound that the record has to support.
• Using F when the Gustilo grade is missing: An open fracture with no documented type defaults to the type I or II character. The routine-healing follow-up is then S52.002E. Query the surgeon rather than assume type III.
• Changing the fracture-type letter mid-episode: Open versus closed and the Gustilo grade are fixed by the original injury. Only the healing tier moves as the episode progresses. A patient coded C at presentation moves to F, J, N, or R later, never to D, G, K, or P.
• Using an initial-encounter character on a follow-up visit: A, B, and C are for active treatment. A patient returning for a wound check or imaging review weeks later is a subsequent encounter. Repeating C on follow-up visits is both a coding error and an audit flag.
• Omitting laterality: S52.002F specifies the left ulna. Submitting a laterality-unspecified code when the side is documented is a specificity error under ICD-10-CM guidelines.
• Submitting S52.002 without a 7th character: S52.002 is not billable. Every claim needs a complete seven-character code, and clearinghouses reject incomplete codes.
• Using the right-ulna code: S52.001F describes the right ulna. When the documented injury is the left ulna, only S52.002F applies. Laterality swaps often originate in copy-paste EHR workflows.

Tracking which of these errors drives the most rework lets a coding team target its retraining. On a proximal ulna episode, audit the fracture-type letter first. It is the one element a follow-up note cannot establish on its own.

Related ICD-10-CM codes: sibling codes and adjacent diagnoses

The table below covers the S52.002 codes a coder is most likely to weigh against S52.002F. It also lists the right-ulna and unspecified-laterality equivalents, because laterality swaps are a frequent source of rejections.

Associated CPT codes for proximal ulna fracture treatment

S52.002F is a diagnosis code and must be paired with a procedure code on every claim. The CPT code reflects what was done at this subsequent encounter, which is usually aftercare rather than definitive fracture treatment. Those procedure codes sit inside the wider full CPT code set, alongside the casting, imaging, and wound-care families this diagnosis draws on.

Two payer rules deserve a check before submission. CPT pairing rules vary by payer, and NCCI edits may bundle certain procedure codes together. Global periods matter more than usual here. A type III open fracture is often treated surgically, so much of the routine aftercare falls inside the surgical package.

Is S52.002F valid for FY2026?

S52.002F is valid for both FY2025 and FY2026, confirmed through the CDC/NCHS ICD-10-CM tool. No description changes affected this code in the FY2026 update cycle. CDC/NCHS manages the update process under CMS oversight, and each October 1 it may add or revise fracture subcodes. So verify the code’s status at the start of every fiscal year.

• FY2025 status: Active and billable
• FY2026 status: Active and billable, with no changes to the S52.002 subcategory in the FY2026 update
• HIPAA validity: Accepted for electronic claims under HIPAA transaction standards when paired with a valid CPT or HCPCS procedure code
• Annual verification: Check the CMS FY update files each October 1, or use the CDC ICD-10-CM web tool for real-time validity lookups

Refresh the encoder and the stored code sets at the start of each fiscal year, so a retired code never reaches a payer. An annual internal audit of S52 usage against the updated guidelines catches what an encoder alone will miss.

How Pabau supports claim submission for fracture codes

In most orthopedic and urgent care practices, a fracture follow-up claim gets assembled twice. The clinician documents the visit in the chart, and a biller then re-keys the patient and insurance details into a separate portal. Every re-keying step is a chance for a mismatched policy number or date of birth. Those mismatches come back as rejections unrelated to the coding itself.

Practice management software like Pabau removes that second pass. Patient and insurance details are validated inside the record before a claim is built. A stale policy number gets caught before submission rather than after. Claims then go out through Pabau’s clearinghouse integrations, including Healthcode in the UK, Claim.MD in the US, and Tyro Health in Australia. Status updates flow back onto the patient’s record, so a biller can see where a claim sits without logging into a separate portal.

For a practice running a high volume of S52 aftercare visits, the result is fewer avoidable rejections from bad patient data. It also means far less time spent chasing claim status. Coding judgment stays with the coder, which is where the 7th character decision belongs.

Spend less time chasing fracture follow-up claims

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Conclusion

Selecting S52.002F correctly depends on four elements. The encounter must be subsequent and the site must be the left proximal ulna. The fracture must be open at Gustilo type IIIA, IIIB, or IIIC, and healing must be routine. Change any one of those and the code changes with it. The mistake to guard against is treating F as a delayed-healing character. Delayed healing on a closed fracture is S52.002G, and delayed healing on this same open fracture is S52.002J.

For practices billing across the S52 family, Pabau supports cleaner claims management from inside the patient record. It validates patient and insurance details, submits the claim, and reports its status back without a second portal. To see how it handles fracture follow-up billing, book a demo.

Continue your research

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Looking for electronic claim submission guidance? Medical claims clearinghouse explains how clearinghouses validate and route claims to payers, and what happens when one is rejected.

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