ICD code S82.491H – Right fibula shaft fracture, delayed healing

Key takeaways

S82.491H covers the shaft of the fibula, not the tibia and not the ankle malleolus.

The H suffix means delayed healing, while a documented nonunion of the same fracture takes M instead.

S82.491H applies to the right fibula only. The left side uses S82.492H and an unspecified side uses S82.499H.

The record must show both a Gustilo type I or II open wound and a physician statement that healing is delayed.

Pabau, a practice management platform, pairs ICD-10-CM code lookup with electronic claim submission through Claim.MD.

ICD-10 Code S82.491H: Official description and classification

ICD-10 Code S82.491H describes “other fracture of shaft of right fibula, subsequent encounter for open fracture type I or II with delayed healing.” The code is billable and specific under ICD-10-CM, and it is valid for the current fiscal year.

It sits within the S82.4 subcategory, which covers fractures of the shaft of the fibula. That subcategory belongs to category S82, fractures of the lower leg including ankle, inside Chapter 19. The table below shows the code’s position within the classification hierarchy.

Coders can verify the current-year validity of this code in the CDC/NCHS ICD-10-CM web tool. It is updated each October 1 to reflect the new fiscal year release.

What the 7th character H means for fracture codes

The 7th character H means subsequent encounter for an open fracture type I or II with delayed healing. Two facts are carried in that single letter. The original wound was graded Gustilo type I or II, and the fracture is taking longer than expected to unite.

Delayed healing is not nonunion. Delayed healing means the fracture is still progressing toward union, just slowly. Nonunion means healing has stalled and is not expected to resume without intervention. That distinction moves the suffix from H to M, and payers audit for it.

The S82 7th-character set is built on two axes: encounter type and fracture status. The table below maps every suffix available to S82.491.

Three distinctions decide whether H is the right letter. First, H covers Gustilo type I or II only. A type IIIA, IIIB, or IIIC wound with delayed healing takes J instead. Second, H covers an open fracture only. A closed fracture with delayed healing takes G. Third, H covers delayed healing only. Once the physician documents nonunion, the suffix becomes M.

Add the encounter sequence to those three and the whole choice becomes a four-step check on the chart. The path below shows where each answer sends the claim.

Anatomical context: Rractures of the shaft of the fibula

The fibula is the slender lateral bone of the lower leg. It runs from just below the knee to the lateral malleolus at the ankle. The shaft is the long middle section between those two ends, and it is the segment S82.4 codes describe.

The fibula carries only a small share of body weight, so an isolated shaft fracture is often treated without surgery. Most are caused by a direct blow to the outside of the leg or by a twisting ankle injury. A high-energy impact that breaks the tibia at the same time is the other common mechanism.

An open wound over the fracture changes the picture, because contamination and soft-tissue damage both slow bone healing. The “other fracture” wording in S82.491H matters too. S82.4 separates displaced and nondisplaced transverse, oblique, spiral, comminuted, and segmental patterns into their own subcategories. S82.49 captures shaft fractures that match none of those named patterns, which makes the operative or radiology description the deciding document.

Open fracture classification under the Gustilo system drives the 7th character. Type I is a wound under 1 cm with minimal soft-tissue damage. Type II is a wound of 1 to 10 cm with moderate soft-tissue damage. Type III involves major soft-tissue disruption and splits into IIIA, IIIB, and IIIC based on periosteal stripping and vascular injury.

Gustilo grading belongs in the operative or emergency note. If the record says only “open fracture” with no grade, the coder cannot assign H and must query the physician. The CMS ICD-10 coding guidelines require the most specific code the documentation supports, so Gustilo classification is not optional detail.

S82.491H vs related codes: Choosing the right code

The S82.491 family runs through the full 7th-character set, and S82.49x covers all three laterality options. The table below compares the codes coders most often confuse with S82.491H.

The AAPC’s ICD-10-CM codebook lookup cross-references each of these against the tabular index. It is a fast way to confirm exact descriptor wording before a claim goes out.

Includes, excludes, and coding notes

Several fracture types are excluded from S82.491H and its parent blocks. Knowing these protects against miscoding adjacent presentations.

• Includes (S82 level): Fracture of malleolus. Ankle-level fibula fractures are coded in S82.6 and S82.8, not in the shaft subcategory S82.4.
• Excludes1 (S82 level): Traumatic amputation of lower leg (S88.-).
• Excludes2 (S82 level): Fracture of foot, except ankle (S92.-). Also periprosthetic fracture around an internal knee prosthesis (M97.1-) or ankle prosthesis (M97.2-).
• Excludes1 (Chapter 19 level): Pathological fracture (M84.4- to M84.6-) and stress fracture (M84.3-).
• Additional code required: An external cause code from Chapter 20 reports the mechanism of injury. The Gustilo grade must be documented before the 7th character can be justified.

Excludes1 means the excluded code cannot be reported with S82.491H for the same condition. Excludes2 means the two conditions are distinct and may legitimately coexist. Pathological fracture is the common Excludes1 trap: a fibular break through a bone metastasis is coded from M84.5-, never from S82.491H.

Documentation requirements for S82.491H

A claim carrying ICD-10 Code S82.491H must be supported by six specific documentation elements. Missing any one of them creates grounds for denial or a CDI query.

• Return visit confirmed: The note must show this is a follow-up encounter for an existing fracture. Initial encounters use A, B, or C.
• Right side confirmed: Laterality documentation is mandatory. “Fibula fracture” with no side stated falls to S82.499H, which carries higher denial risk.
• Shaft location confirmed: The note must place the fracture in the shaft of the fibula. The fibular head, the neck, and the lateral malleolus all code elsewhere.
• Fracture pattern reviewed: S82.49 applies only when the pattern is not one of the named types in S82.42 through S82.46. Check the radiology report before defaulting to “other.”
• Open fracture Gustilo type I or II confirmed: The operative or emergency note must state the grade. “Open wound” on its own is not enough.
• Delayed healing confirmed: The physician must state that union is delayed, supported by imaging at a follow-up timepoint. A note that says nonunion moves the code to S82.491M.

ICD-10-CM sets no week count for delayed healing, so the physician’s own statement is the source of truth. That is why “callus formation slower than expected” in a radiology impression does not code to H by itself. The treating physician has to adopt the finding in the encounter note.

When documentation is ambiguous, query before assigning the H suffix. A query answered in an addendum costs far less than a denial worked three weeks later.

CPT codes commonly billed with S82.491H

The CPT codes paired with ICD-10 Code S82.491H depend on whether the encounter involves continued fracture management, imaging, bone stimulation, physical therapy, or surgical fixation. Verify current National Correct Coding Initiative (NCCI) edits before billing any combination, because bundling rules change annually.

Pairing frequency varies by payer and setting. The combinations above reflect common clinical pathways under AMA CPT guidelines. Confirm that NCCI edits do not bundle any pair before you submit. Each procedure code above has its own entry in our CPT codes library, with the full descriptor and the billing notes attached.

Common claim denial reasons and how to avoid them

Claims carrying ICD-10 Code S82.491H are denied for a predictable set of reasons. Each one traces back to a detail the note left out or a letter the coder picked wrong.

A systematic approach to denial management in healthcare moves an orthopedic billing team from correcting claims to preventing them. Practices running several orthopedic providers benefit from tracking denials by 7th character, because that shows which physician notes keep omitting healing status.

Sequela vs subsequent encounter: Which suffix applies

The S suffix (sequela) and the H suffix (subsequent encounter) are mutually exclusive. Choosing S82.491S when H is correct is one of the audit risks flagged in ICD-10-CM Official Guidelines Section I.C.19.a.

Subsequent encounter applies while the fracture is still under active management, no matter how many months have passed. Active management includes cast or boot changes, surgical planning, bone stimulator therapy, and physical therapy aimed at the fracture. As long as the fracture itself is being treated, a subsequent encounter suffix applies.

Sequela applies only once the fracture has resolved and the patient returns with a residual late effect. A patient with chronic lateral leg pain two years after a healed fibular shaft fracture would list the pain diagnosis first, then S82.491S. The fracture is no longer the condition being treated.

• Use H when: This is a return visit, the fracture was open type I or II, and the physician documents delayed healing.
• Use S when: The fracture has healed and the patient presents with a documented late effect of it.
• Never use both: H and S cannot be reported together for the same fracture episode.

Coding S82.491H for specific clinical scenarios

The four scenarios below follow one patient across an episode of care. Each includes the rationale for the code assignment.

Scenario 1: Orthopedic follow-up at 16 weeks post-injury

Patient has a right fibular shaft fracture with a Gustilo type I open wound documented at the original presentation. Films at 16 weeks show early callus, but less than expected for the timepoint. The physician documents delayed union and continues nonoperative management.

Code assignment: S82.491H as the principal diagnosis. Add the external cause code for the mechanism with a D suffix at this subsequent encounter, for example W18.31XD. No aftercare Z code is needed, because the 7th character already reports the encounter type.

Scenario 2: Physical therapy visit for the same patient

The same patient attends physical therapy for gait retraining and ankle range of motion while the fracture is still uniting slowly.

Code assignment: S82.491H as the primary diagnosis on the physical therapy claim. CPT 97110 (therapeutic exercise) or 97530 (therapeutic activities) as the procedure code, depending on what was delivered. Carry the same diagnosis across every therapy visit in the episode, and change it only when the physician’s healing statement changes.

Scenario 3: Bone stimulator prescription encounter

The physician prescribes a noninvasive electrical bone growth stimulator to support union. The prescription is written at a separate office visit.

Code assignment: S82.491H as the primary diagnosis, with the appropriate E&M code for the office visit. On the separately filed DME claim, HCPCS code E0747 covers a noninvasive electrical osteogenesis stimulator for a nonspinal site. HCPCS code E0760 covers the low-intensity ultrasound device. Prior authorization is common here, so check the LCD before prescribing.

Scenario 4: Pre-operative assessment for fixation of the delayed union

Conservative management has not produced union, and the patient is cleared for internal fixation. The pre-operative assessment is billed before the surgical encounter.

Code assignment: S82.491H as the primary diagnosis, with the appropriate E&M code for the pre-operative evaluation. The surgery itself is reported with CPT 27784 and the same diagnosis. If the surgeon’s note reclassifies the fracture as a nonunion, the diagnosis moves to S82.491M from that encounter onward.

How Pabau keeps S82.491H claims in step with the chart

Most coding teams work this code across three systems. The chart sits in the EHR, the code is checked in a separate reference tool, and the claim is keyed into a billing portal. A 7th character that changes mid-episode then has to be carried by hand into each one.

Pabau, a practice management platform built for orthopedic, rehabilitation and allied health practices, holds all three in one record. Its claims management software searches the ICD-10-CM set while the note is open, so the coder picks S82.491H against the documentation that supports it. Claims then submit electronically through the Claim.MD clearinghouse, with no rekeying step in between.

When the physician records nonunion at a later visit, the coder moves the next claim to S82.491M. The encounters already billed stay as they were. Denials come back into the same record, so a practice can sort them by 7th character and see which provider’s notes keep omitting healing status.

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Conclusion

ICD-10 Code S82.491H is specific and billable, and it is denied most often when the record does not carry the two facts the suffix asserts. Those facts are a Gustilo type I or II open wound at the original injury, and a physician statement that healing is delayed.

Get either one wrong and the correct code is a different letter. A closed fracture takes G, a higher Gustilo grade takes J, and a documented nonunion takes the M suffix. The practical move is to set the query trigger before the claim goes out rather than after it comes back.

That habit is easier to hold when code lookup and claim submission share one record. Book a demo to see how Pabau keeps 7th-character changes in step with the chart on orthopedic claims.

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