ICD code S82.033P – Displaced transverse patellar fracture with malunion

Key takeaways

S82.033P is a billable 7-character ICD-10-CM code, valid from FY2016 through the current FY2027 code set.

The 7th character P means a subsequent encounter for a closed fracture with malunion: the patella has healed, but out of alignment.

Common errors include an initial-encounter suffix (A) at follow-up, confusing P with K (closed nonunion), or using P for an open fracture.

Pabau’s claims management software supports ICD-10 code lookup and claim submission through Claim.MD, so orthopedic practices see fewer denials on follow-up fracture claims.

ICD-10 Code S82.033P: Quick reference and billable status

ICD-10 Code S82.033P is a valid, billable ICD-10-CM code, effective from October 1, 2015 (FY2016) and unchanged in the current FY2027 code set.

It reports a follow-up visit for a closed, displaced transverse kneecap fracture that has healed out of alignment, side unspecified. It carries a full 7-character structure and is accepted for diagnosis reporting on CMS-1500 and 837P claims.

What does S82.033P mean? Breaking down the code

S82.033P describes a displaced transverse patellar fracture, side unspecified, seen at a follow-up visit. The original fracture was closed, and it has since healed with malunion. Each character carries a distinct clinical meaning, and misreading any one of them produces the wrong code.

• S – Injury chapter (Chapter 19, S00-T88)
• 82 – Fracture of lower leg, including ankle (category S82)
• 0 – Fracture of patella (subcategory S82.0)
• 3 – Transverse fracture of patella (S82.03)
• 3 – Displaced, unspecified patella (S82.033; the nondisplaced equivalent is S82.036)
• P – 7th character: subsequent encounter for closed fracture with malunion

Note that S82.033 encodes unspecified laterality. Right-side displaced transverse patellar fractures use S82.031-, and left-side fractures use S82.032-. If the operative report or imaging specifies a side, use the laterality-specific code rather than S82.033P.

Understanding the 7th character “P”: Subsequent encounter for closed fracture with malunion

The 7th character “P” means a follow-up visit for a closed fracture that imaging shows has healed out of alignment. The ICD-10-CM Official Guidelines published by CMS direct coders to report fracture complications with a subsequent-care 7th character. Nonunion takes K, M, or N, and malunion takes P, Q, or R.

Malunion means the fracture has united, but in a position that alters alignment or the joint surface. On the patella, that often shows as an articular step-off behind the kneecap.

Nonunion is the opposite problem: the fracture has failed to unite at all. That distinction, plus whether the original fracture was closed or open, drives the 7th character.

Key distinction: For a closed patellar fracture that has failed to unite, the correct code is S82.033K, not S82.033P. P applies only when a closed fracture has healed, but in a malaligned position.

If the original fracture was open, malunion moves to Q (type I or II) or R (type IIIA, IIIB, or IIIC). The grid below maps every follow-up letter by fracture type and healing status.

Full S82.033 code family: All 7th character variants

The S82.033 subcategory covers displaced transverse fractures of the unspecified patella across every encounter type and healing status. The table below lists every valid variant according to the CDC/NCHS ICD-10-CM code tool.

Clinical scenario: when to use ICD-10 Code S82.033P

A patient returns for orthopedic follow-up five months after a closed displaced transverse patellar fracture was fixed with tension band wiring. X-rays show the fracture has united, but with an articular step-off. The patient reports anterior knee pain on stairs.

The surgeon documents malunion and plans a corrective osteotomy with hardware revision. This is the scenario S82.033P was built for. Bone grafting to stimulate healing belongs to nonunion care, not to this code.

Work through the selection logic in sequence:

1. Confirm it is a subsequent encounter. The initial fracture care has already been coded (S82.033A for the initial closed-fracture visit). Today’s visit addresses a complication of a fracture that was already treated.
2. Confirm malunion is explicitly documented. The imaging report or surgeon’s note must state malunion, or describe a healed fracture in malalignment. “Slow healing” supports S82.033G, and failed union supports S82.033K.
3. Confirm the original fracture was closed. Closed fractures carry no Gustilo type. If the original fracture was open, use S82.033Q (type I or II) or S82.033R (type IIIA, IIIB, or IIIC).
4. Confirm displaced and transverse. If a different fracture pattern is documented (comminuted, longitudinal, osteochondral), the S82.03 group does not apply.
5. Confirm laterality. S82.033P specifies an unspecified side. If the chart clearly states left or right, use S82.031P (right) or S82.032P (left) instead.

Documentation requirements for S82.033P

A claim with ICD-10 Code S82.033P needs a medical record that supports each part of the code. Medicare and most commercial payers expect the record to confirm malunion, not only a follow-up visit, before they pay for corrective surgery.

The record must contain all of the following:

• Fracture type and displacement. An imaging report or operative note explicitly describing a transverse fracture pattern and displaced alignment.
• Closed fracture status. Documentation from the initial encounter that the skin was intact. Closed fractures carry no Gustilo type, so a Gustilo grade in the chart points to Q or R instead.
• Malunion confirmation. A radiology report or surgeon’s note confirming the fracture has healed in malalignment, such as an articular step-off or angulation. A clinical impression alone, without imaging support, is insufficient for most payers.
• Subsequent encounter confirmation. A note or coding flag confirming this visit is not the first active treatment episode. If no initial-encounter code has been billed, the payer may question whether P is appropriate.
• Laterality resolution. If the chart specifies a side, the laterality-specific code (S82.031P or S82.032P) must be used rather than S82.033P.

Missing any of these elements raises the risk of a medical necessity denial or a request for additional documentation from Medicare. Practices using claims management software with built-in ICD-10 code validation can flag incomplete documentation before the claim leaves the office.

Excludes notes and additional-code instructions for S82.033P

The S82 category and Chapter 19 carry notes that restrict how S82.033P is used. Applying this code when an exclusion applies produces an invalid claim.

Excludes 1 (cannot be coded together):

• Traumatic amputation of lower leg (S88.-)

Excludes 2 (not included here; code additionally if present):

• Fracture of foot, except ankle (S92.-)
• Periprosthetic fracture around internal prosthetic implant of knee joint (M97.1-) – fractures around knee replacements take M97 codes, not S82
• Periprosthetic fracture around internal prosthetic ankle joint (M97.2)

Chapter 19 instructions:

• Use a secondary code from Chapter 20 (external causes of morbidity) to show the cause of the injury
• Use an additional code to identify any retained foreign body (Z18.-), if applicable

The S82 codes cover traumatic fractures only. A patellar fracture caused by disease, such as osteoporosis or metastatic bone disease, or by repetitive stress is coded in category M84 instead. The documentation must establish a traumatic cause before S82.033P applies.

Common coding errors with ICD-10 Code S82.033P

These five errors recur on displaced transverse patellar fracture claims at subsequent encounters. Each one is visible in the code itself, so a pre-submission check catches it.

Payer requirements and prior authorization for S82.033P claims

Medicare pays physician services for subsequent-encounter fracture care under the Physician Fee Schedule. For malunion cases billed with ICD-10 Code S82.033P, payers expect medical necessity documentation. It should show how the malalignment affects function and what correction is planned.

Common reasons Medicare and commercial payers deny S82.033P claims include:

• Encounter type mismatch. An initial-encounter CPT code (fracture care code) billed alongside a subsequent-encounter diagnosis code, or vice versa.
• Missing imaging documentation. Malunion requires objective confirmation. A note stating “patient reports knee pain” without a radiology report describing the malalignment rarely satisfies medical necessity criteria.
• Wrong code family. Using S82.033P when the original fracture was pathological (M84.5-) or stress-related (M84.3-).
• No prior claim history. Some payers flag a subsequent-encounter code when no initial-encounter claim for the same fracture appears in the patient’s claim history.

Corrective surgery for malunion, such as an osteotomy or hardware revision, often requires prior authorization, depending on the payer. Submit the imaging report, the surgeon’s assessment, and the original fracture care claims as supporting documentation.

Pabau’s Claim.MD clearinghouse integration keeps that packet moving. It checks eligibility in real time, submits the claim electronically, and brings claim statuses and remittance advice back into Pabau.

Associated CPT codes for displaced transverse patellar fracture malunion encounters

ICD-10 Code S82.033P is a diagnosis code. It pairs with CPT codes that describe the services provided at the subsequent encounter. The table below lists CPT codes commonly billed alongside S82.033P, based on the CMS Physician Fee Schedule and AMA CPT guidelines.

Imaging usually comes first on a malunion claim. CPT 73564 reports the four-view knee series that confirms the malalignment. If the correction starts with taking out old tension band wiring, CPT 20680 reports that hardware removal.

Local coverage determinations (LCDs) vary by Medicare Administrative Contractor. Always verify that the planned CPT code is covered for S82.033P under the relevant MAC’s LCD before submitting.

Pabau sends claims through a medical claims clearinghouse, so a rejected CPT and diagnosis pairing comes back to the same billing record.

ICD-9-CM crosswalk for S82.033P

ICD-9-CM did not have 7th character specificity for encounter type or healing status, so the crosswalk from S82.033P to ICD-9 is approximate.

According to ResDAC’s ICD coding guidance for Medicare files, General Equivalence Mappings (GEMs) are one-to-many by design. One ICD-10 code often maps to several ICD-9 candidates.

Do not use GEM crosswalks for active billing. They exist for historical data analysis and research purposes. For current claims, always code from the ICD-10-CM tabular list directly.

How Pabau keeps S82.033P claims accurate from chart to claim

Malunion denials usually start where the chart and the claim disagree. The surgeon documents a closed fracture that healed out of alignment, but the claim goes out with a K, an A, or an unspecified side.

Pabau keeps the clinical note, the imaging attachments, and the ICD-10 code in the same patient record. Your coder checks the 7th character against the surgeon’s words before billing. Claims then go out through the Claim.MD integration, with eligibility checks, claim statuses, and remittances tracked in one place.

The result is fewer resubmissions on follow-up fracture claims and faster payment for corrective care.

Reduce fracture coding denials with Pabau

Pabau integrates with Claim.MD to submit ICD-10-coded claims electronically and verify eligibility in real time. Claim statuses and remittances flow back into Pabau, so your orthopedic practice gets paid faster.

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Conclusion

S82.033P is narrow by design. It fits only a closed, displaced transverse patellar fracture that has healed out of alignment, at a visit for that complication. Get the closed status, the malunion finding, and the side right in the record, and the code follows.

Let the surgeon’s findings choose the letter. A follow-up visit alone never justifies P, but malunion documented on imaging does.

Pabau’s denial management workflows help orthopedic practices track S82.033P claims through Claim.MD and resubmit cleanly. To see how Pabau keeps malunion claims clean from chart to payment, book a demo.

Continue your research

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Looking for guidance on the full claim submission workflow? What makes a clean claim walks through the data elements payers validate before adjudicating, including ICD-10 code completeness and encounter-type consistency.

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