ICD-10 Code S82.845D: Nondisplaced bimalleolar fracture

Key takeaways

S82.845D is a billable ICD-10-CM code for a nondisplaced bimalleolar fracture of the left lower leg, subsequent encounter for closed fracture with routine healing.

Bimalleolar fractures live under S82.84, inside the S82.8 subcategory for other fractures of lower leg. They are not coded from S82.4 (shaft of fibula), S82.5, or S82.6.

In the S82.84 series the 6th character carries both displacement and side, so 5 means nondisplaced and left. There is no separate laterality character.

The 7th character D means a subsequent encounter for a closed fracture that is healing normally. E and F describe open fractures, so they never belong on a closed ankle fracture claim.

Practice management software like Pabau attaches ICD-10 codes to the patient record, so billing teams submit claims without manual re-entry.

ICD-10 Code S82.845D is a billable ICD-10-CM code for a nondisplaced bimalleolar fracture of the left lower leg. It covers a subsequent encounter for a closed fracture with routine healing.

The code is current in the CMS ICD-10-CM code set for FY2026. One code carries five facts for the payer: bimalleolar, nondisplaced, left, closed, and a follow-up visit healing as expected.

The S82.84 series has one feature that catches coders out. Its 6th character sets displacement and side together, so 5 means nondisplaced and left at the same time. Coders who expect a separate laterality character go looking for one that does not exist.

This reference walks through the character-by-character breakdown, the sixteen 7th characters, the code hierarchy, the near-identical siblings, and how S82.845D behaves on a claim. It is written for medical coders, orthopedic billing teams, and physical therapy practices billing ankle fracture follow-ups.

What does S82.845D mean? Breaking down the code

Every character in ICD-10 Code S82.845D carries a specific meaning. A coder who can read the structure verifies a claim in seconds. A coder who cannot lands in a sibling code that flips the side, the displacement status, or the open versus closed status.

The 6th character is the one coders misread most. In the S82.84 series it encodes displacement and side together, so there is no separate laterality digit to check. All six combinations sit in one grid below. Submitting S82.845D for a right ankle therefore gets two facts wrong at once.

The 7th character D: Subsequent encounter with routine healing

Every code in the S82.845 family needs a 7th character before it can be billed, and sixteen options exist. Each one describes a different combination of encounter type, open or closed status, and healing outcome. Pick the wrong one and the claim describes an encounter that never happened.

Character D means one thing only: the patient is back for follow-up, the fracture is closed, and it is healing as expected. The CDC/NCHS ICD-10-CM tool confirms the full extension list for this subcategory. D does not cover delayed healing, nonunion, or malunion, and it never covers an open fracture.

Read down the closed-fracture rows and the logic becomes easy to hold. Only A, D, G, K, and P belong on a closed ankle fracture. The remaining characters all describe an open wound communicating with the fracture site. The AAPC ICD-10-CM lookup gives year-specific validation for each code and its valid extensions.

Anatomical context: Bimalleolar fracture of the lower leg

A bimalleolar fracture breaks both the medial malleolus and the lateral malleolus. The medial malleolus is the bony prominence on the inner ankle, formed by the distal tibia.

The lateral malleolus is the outer prominence, formed by the distal fibula. Together they hold the ankle mortise, so this pattern is treated as an unstable ankle injury even when the fragments have not moved.

That anatomy explains where the code lives. Because the injury spans two bones, ICD-10-CM does not file it under either bone. It sits in S82.8, the residual subcategory for other fractures of the lower leg, at S82.84.

• Mechanism of injury: usually a twisting or rotational force on a planted foot, common in falls, sports, and stair injuries
• Displacement status: nondisplaced means the fragments remain in anatomical alignment, so the fracture itself needs no surgical repositioning
• Fracture type default: a fracture not documented as open is coded as closed, per ICD-10-CM Official Guidelines Section I.C.19
• Laterality: S82.845D specifies the left lower leg, and using it for a right-sided injury is a compliance error
• Subsequent encounter: applies from the follow-up visit onward, once the initial treatment phase of casting, splinting, or fixation has begun
• One code, not two: report the single bimalleolar code instead of pairing a medial malleolus code with a lateral malleolus code

Bimalleolar, isolated malleolar, or shaft: Choosing the right S82 subcategory

Most bimalleolar coding errors happen before the 7th character is ever chosen. The coder searches the tabular list for “malleolus” or “fibula” and lands in a neighboring subcategory.

From there the result is a perfectly formed code for the wrong injury. The table below shows the S82 subcategories that get confused with S82.84 and what each one covers.

The S82.4 row is worth a second look, because it is the trap that catches the most coders. S82.4 codes carry the same 7th characters and the same nondisplaced wording as S82.84, so a mistyped code still validates cleanly. It just bills the wrong bone at the wrong level of the leg.

S82.845D in the ICD-10-CM code hierarchy

Knowing where ICD-10 Code S82.845D sits in the tree makes it easy to move sideways to other lateralities, displacement statuses, and encounter types. The hierarchy below runs from chapter level down to the fully specified billable code.

Every fracture code in Chapter 19 shares this shape. Reading the tree stops coders from submitting S82.845, which is not billable on its own. It also keeps the 7th character in view as a required element rather than an optional suffix. The same shape repeats across the wider ICD-10-CM code library, so the reading habit transfers to any chapter.

Related and alternative ICD-10 codes

S82.845D sits in a tight family of near-identical codes. Picking the wrong sibling is the most common bimalleolar coding error after subcategory confusion. The table below maps the alternatives coders reach for most often, so the documentation can be cross-checked before submission.

Crosswalking between these siblings is a habit worth building. Before submission, read the code back against three lines in the note: which malleoli, which side, and how the fracture is healing. If any of the three is missing from the record, the sibling code is a guess.

Coding guidelines and compliance notes

The ICD-10-CM Official Guidelines for Coding and Reporting, Section I.C.19, govern every fracture coding decision. Five of its rules do most of the work on an S82.845D claim.

Orthopedic and sports medicine billing teams tend to keep fracture codes on a standing audit list. The 7th character rules give a claim sixteen ways to describe the same visit, and only one of them matches the note.

• Open versus closed default: a fracture not documented as open is coded as closed, per Section I.C.19. S82.845D reflects a closed fracture, so an open wound at the fracture site moves the claim to E, F, H, or J instead.
• Displaced versus nondisplaced default: where the note does not specify displacement, the guidelines direct coders to default to displaced. S82.845D states nondisplaced, so the record has to support it.
• Subsequent versus initial encounter: a subsequent encounter starts once the patient is receiving routine care for an injury already treated. Cast changes, fracture checks, and physical therapy visits all qualify. Character A applies only while active treatment of the fracture is still under way.
• Laterality verification: the 6th character 5 designates the left side as well as nondisplaced status. Check it against the operative note, the clinical note, or the imaging report every time.
• Sequencing with external cause codes: report the fracture code first, then the external cause code that captures the mechanism. That means a W-code for a fall or a V-code for a transport accident. Payers reviewing musculoskeletal claims increasingly look for the pairing.

How the code works on a claim

Getting ICD-10 Code S82.845D paid depends on three things. Pair it with the right procedure codes and document the encounter type clearly.

Then route the claim through a clearinghouse that screens format and eligibility first. Most fracture checks land on an office visit code such as 99213, so the diagnosis and the service have to describe the same visit.

• CPT pairing: follow-up visits usually pair S82.845D with an evaluation and management code such as 99213 or 99214. Rehabilitation encounters pair it with physical therapy codes such as 97110 and 97530. Cast work pairs it with 29405 for applying a short leg cast and 29700 for removing or bivalving that cast.
• Documentation requirements: the note must confirm both malleoli, nondisplaced status, left side, closed fracture, and routine healing. A missing element leaves the code unsupported by the record, which is what auditors look for.
• Common denial triggers: the three usual patterns are an initial-encounter character left on a follow-up claim, a laterality mismatch, and a missing external cause code. Screening for all three at submission prevents avoidable rework.
• Payer acceptance: S82.845D is accepted across Medicare, Medicaid, and commercial payers as a billable, specific ICD-10-CM code. Check the relevant Local Coverage Determination for any payer-specific requirement.

How practice management software like Pabau supports accurate fracture coding

Fracture coding is not hard on any single visit. It gets hard across a treatment episode. The diagnosis has to change as the patient heals, while the side and the displacement status stay fixed.

Practice management software like Pabau keeps that episode in one record. The coder can see the initial encounter, every follow-up, and the imaging that supports the nondisplaced call.

Orthopedic and physical therapy teams get the same benefit from keeping the treatment plan next to the code. Keep the therapist’s note and the diagnosis in the same chart and the link between them is visible at the point of coding. Nobody has to reconstruct it at appeal.

Pabau submits electronic claims through Claim.MD, our US clearinghouse partner, which reaches thousands of US payers. The integration also supports real-time eligibility checks and 835 electronic remittance advice.

A billing team can submit an S82.845D claim, take the remittance back in, and reconcile a denied fracture encounter without leaving the platform. Pabau’s claims management without re-entry works from the same record that carries the clinical note.

Manage ICD-10 codes and fracture claims in one place

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Conclusion

ICD-10 Code S82.845D is straightforward once you read it in two halves. The first half, S82.845, fixes the injury: bimalleolar, nondisplaced, left. The second half, the character D, fixes the encounter: follow-up visit, closed fracture, healing normally. Get to S82.84 first and the rest follows.

The habit worth keeping is the re-read at every follow-up. Side and displacement stay fixed for the whole episode, but the 7th character moves. A claim carrying last visit’s character describes the wrong encounter. Book a demo to see how Pabau keeps the note, the code, and the claim on one record for every fracture follow-up.

Continue your research

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