ICD-10 code S82.155P: left tibial tuberosity fracture guide

ICD-10 code S82.155P identifies a nondisplaced fracture of the left tibial tuberosity – the bony prominence just below the knee where the patellar tendon attaches – at a subsequent encounter where the fracture has healed with malunion. This guide breaks down the code’s structure, correct clinical use, and the billing codes practices commonly pair with it.

Key Takeaways

ICD-10 code S82.155P describes a nondisplaced fracture of the left tibial tuberosity, subsequent encounter for closed fracture with malunion – a billable ICD-10-CM code valid for Medicare, Medicaid, and most commercial payers.

The 7th character P specifically designates a subsequent encounter where the fracture has healed with malunion – meaning it united, but in an abnormal position – which must be clinically or radiographically confirmed before coding.

Common coding error: confusing 7th character P (malunion) with K (nonunion) – these represent distinct complications with different clinical and reimbursement implications.

Practice management software like Pabau helps orthopedic and physical therapy practices document the correct ICD-10 diagnosis code – including the right 7th-character encounter type – at the point of care, so billing staff are not correcting mismatched codes after the claim has already gone out.

ICD-10 code S82.155P: quick reference

S82.155P is a valid, billable ICD-10 code S82.155P for the subsequent encounter for a nondisplaced fracture of the left tibial tuberosity with malunion.

It is listed in the ICD-10-CM tabular list maintained by the National Center for Health Statistics (NCHS), part of the CDC, in coordination with the Centers for Medicare and Medicaid Services (CMS). The code is accepted by Medicare, Medicaid, and most commercial payers for FY2026.

What does S82.155P mean? Breaking down the code

Every character in ICD-10 code S82.155P carries a specific clinical meaning. Coders who understand the structure can select the right 7th character the first time, avoiding claim rejections from incorrect encounter designations.

The base code S82.155 is never submitted alone. It requires a 7th character to be a complete, billable code. The CDC/NCHS ICD-10-CM web tool confirms that S82.155P is a valid leaf-level code, meaning it has no further child codes and can be used directly on claims.

Clinical description: nondisplaced fracture of left tibial tuberosity with malunion

The tibia is the primary weight-bearing bone of the lower leg, running from the knee joint to the ankle. The tibial tuberosity is a bony prominence on the proximal (upper) tibia, just below the knee, where the patellar tendon attaches.

Fractures of the tuberosity are typically avulsion-type injuries caused by a forceful quadriceps contraction, such as jumping or sprinting, rather than direct trauma to the mid-shaft (diaphysis).

Nondisplaced means the bone fragments remain in anatomical alignment at the time of the fracture. The cortex may be cracked or completely broken, but the two ends have not shifted relative to each other. This distinguishes it from displaced fractures, where fragments separate, angulate, or rotate.

Malunion is a healing complication, not a descriptor of the original injury. It occurs when a fracture consolidates but in a position of abnormal alignment: rotational deformity, angulation, or shortening. Clinically, malunion can produce gait disturbance, joint stress, pain with weight-bearing, and reduced range of motion.

Before coding the 7th character P, the treating provider must document malunion through clinical assessment or radiographic imaging. Coders cannot infer malunion without physician documentation.

• Nondisplaced at fracture: bone fragments in correct position initially
• Malunion at healing: consolidation in abnormal alignment
• Left-side laterality: the 6th character (5) confirms the left tibia – right side would be S82.154P
• Tibial tuberosity, not shaft: S82.155 falls within the fracture-of-upper-end-of-tibia range (S82.10-S82.19); true tibial shaft (diaphyseal) fractures are coded separately under the S82.2- subcategory

Understanding the 7th character P: subsequent encounter with malunion

Per the ICD-10-CM Official Guidelines for Coding and Reporting (Section I.C.19.c), fracture codes in the S80-S99 range require a 7th character that specifies the episode of care and the status of healing. This system replaced the older ICD-9-CM distinction between acute and aftercare visits.

The 7th character is the primary mechanism for indicating whether a provider is seeing the patient for an initial injury or a follow-up visit. The same logic governs related fracture codes, such as S82.232M for the tibial shaft.

The 7th character applies to any provider treating the condition, not just the initial treating physician. For example, an orthopedic surgeon, a physical therapist, or a sports medicine specialist attending a follow-up visit for a malunited tibial fracture should all use the subsequent encounter character.

All valid 7th character variants for S82.155

Note that H, J, M, N, Q, and R characters also apply to open fracture types with delayed healing, nonunion, and malunion respectively. The table above covers the most clinically common characters for closed tibial tuberosity fractures. The full tabular list is available via the AAPC Codify ICD-10-CM lookup.

When to use S82.155P: coding guidelines and clinical scenarios

The ICD-10-CM Official Guidelines define the subsequent encounter as care of the condition during healing, recovery, or rehabilitation, not limited to the surgeon who performed the initial repair. Any provider treating the patient after the initial encounter uses the appropriate subsequent character. For practices managing these physiotherapy practice compliance requirements, understanding this rule prevents under-coding and claim denials.

Use S82.155P when all four conditions are true:

1. The fracture involves the tibial tuberosity (the proximal tibia, just below the knee) on the left side
2. The fracture was nondisplaced (fragments did not shift at the time of original injury)
3. The encounter is a follow-up visit – the initial encounter has already occurred
4. The treating provider (or radiograph) has documented malunion

S82.155P in common clinical scenarios

These scenarios illustrate appropriate use for orthopedic and rehabilitation providers. Physical therapists with specific physical therapy documentation requirements should confirm that malunion is documented by the referring or supervising physician before using this code independently.

• Orthopedic follow-up visit: patient presents 12 weeks post-fracture; imaging shows the tibial tuberosity healed with a few millimeters of proximal displacement and mild angulation. Surgeon documents malunion. Appropriate code: S82.155P.
• Physical therapy for gait disturbance: PT receiving a referral for rehabilitation following confirmed left tibial tuberosity malunion. The PT uses S82.155P as the primary diagnosis code throughout the rehab episode.
• Pre-surgical planning visit: orthopedic surgeon evaluating the need for corrective osteotomy for a symptomatic left tibial tuberosity malunion. S82.155P captures the diagnosis at this visit.
• Imaging follow-up: radiologist or ordering provider reviewing serial X-rays confirming malunion during the healing period. S82.155P is appropriate once malunion is documented.

Three coding errors account for most claim rejections and audits involving fracture malunion codes. Accurate scheduling and appointment management systems that flag encounter type at the point of care reduce these mistakes before they reach the claim.

Payers audit fracture codes for consistency between 7th character selection and clinical documentation. A claim submitted with S82.155P for malunion should be supported by a chart note or radiology report confirming abnormal alignment. Without that documentation, payers may request records or deny the claim.

Related and comparable ICD-10-CM codes

Coders frequently need to distinguish S82.155P from closely adjacent codes in the S82 fracture category. The same laterality, displacement, and encounter-type logic applies to fracture codes elsewhere in the body, such as S92.301K for the foot.

The S82.155K versus S82.155P distinction is the most common source of coding errors. Nonunion (K): the fracture never consolidated, leaving a gap or pseudoarthrosis. Malunion (P): the fracture did heal, but the bone united in a mechanically or cosmetically unacceptable position.

The clinical picture, imaging findings, and provider documentation drive the correct selection. The same specificity requirement shows up across other orthopedic ICD-10-CM categories, such as M16.7.

Billing and reimbursement considerations for S82.155P

S82.155P is a valid, billable code accepted by Medicare, Medicaid, and most commercial payers for FY2026. Practice management software helps clinicians document and select the correct diagnosis code – including the right 7th-character encounter type – at the point of care, so billing staff are not left correcting mismatched codes after the fact.

Common CPT codes paired with this diagnosis include:

• 27540 – Open treatment of intercondylar spine(s) and/or tuberosity fracture(s) of the knee, includes internal fixation when performed – used when surgical correction of the malunited tibial tuberosity is performed
• 97110 – Therapeutic exercises – commonly billed by physical therapy for rehabilitation of gait disturbance secondary to malunion
• 97530 – Therapeutic activities – for functional retraining in PT following malunion correction
• 73564 – Radiologic examination, knee, complete (4 or more views) – imaging to confirm or monitor tuberosity malunion

CPT codes change annually. Verify current-year validity against the AAPC CPT lookup or your encoder before submission. For orthopedic practices, private practice billing features that automate claim scrubbing can flag mismatched encounter types before submission.

MS-DRG grouping: When S82.155P appears on an inpatient claim, the DRG assignment depends on whether a procedure code is present and the patient’s overall comorbidity profile. DRG assignments are subject to annual IPPS updates, so confirm current grouping with your facility coding team.

Sequencing guidance: When malunion is the primary reason for the encounter, such as a visit specifically to evaluate or treat the malunion, S82.155P should be sequenced as the principal diagnosis. If malunion is an incidental finding during treatment for another condition, sequence it as a secondary code.

Good practice management workflows tie the diagnosis hierarchy in each note to the billing team’s sequencing decisions at claim time.

Reduce fracture coding errors with Pabau

Pabau helps orthopedic and physical therapy practices document the correct ICD-10 diagnosis code at the point of care, with encounter-type prompts that guide clinicians to the right 7th character – so your billing team spends less time correcting codes and more time on patient care.

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Fracture malunion codes are rejected more often because of missing documentation than payer policy issues. Applying S82.155P correctly requires confirmed clinical or radiographic evidence of malunion, a subsequent encounter context, and left-side laterality, all traceable to physician documentation before the code goes on a claim.

For orthopedic and physical therapy practices, Pabau’s physical therapy EMR integrates clinical documentation with billing workflows, making it straightforward to document accurate diagnosis codes and the correct encounter type at the point of care – before the note ever reaches the billing team. To see how it works in practice, book a demo.

Continue your research

Managing compliance for musculoskeletal practices? Mandatory compliance for physiotherapy clinics covers documentation and audit requirements for PT providers in the UK and internationally.

Billing for post-fracture bracing? L2820 covers the soft interface component billed alongside orthotic devices used during knee and lower-leg fracture recovery.

Coding other orthopedic specificity requirements? M16.6 shows how the same laterality rules apply to secondary osteoarthritis of the hip.

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