2026 ICD-10-CM Diagnosis Code S82.146KNondisplaced bicondylar fracture of unspecified tibia, subsequent encounter for closed fracture with nonunion

ICD-10-CM Codes›S00–T88›S80-S89›S82

ICD-10-CM S82.146K
CMSSource: CMS FY 2026 ICD-10-CM dataset · Effective Oct 1, 2025 – Sep 30, 2026

S82.146K is a billable ICD-10-CM diagnosis code for nondisplaced bicondylar fracture of unspecified tibia, subsequent encounter for closed fracture with nonunion. The 7th character K reports a subsequent encounter for a fracture that has failed to heal, called a nonunion. It is valid on HIPAA claims for fiscal year 2026 (October 1, 2025 through September 30, 2026) and groups to MS-DRG 564 through 566. The code is flagged as an unspecified code, since codes identifying laterality exist in the same family and exempt from POA reporting. In AHRQ's Clinical Classifications Software (CCSR), this diagnosis falls under Fracture of lower limb (except hip), subsequent encounter.

Code Identity

ICD-10-CM Code
S82.146K
Billable Status
Yes — Valid for Submission
Code Describes
Nondisplaced bicondylar fracture of unspecified tibia, subsequent encounter for closed fracture with nonunion
Short Description
Nondisp bicondylar fx unsp tibia, 7thK
Parent Code
S82.146
Nondisplaced bicondylar fracture of unspecified tibia

Code Classification

ChapterS00–T88Injury, poisoning and certain other consequences of external causes
SectionS80-S89Injuries to the knee and lower leg
CategoryS82Fracture of lower leg, including ankle
This CodeS82.146KNondisplaced bicondylar fracture of unspecified tibia, subsequent encounter for closed fracture with nonunion

Code EditsBilling

Medicare Code Editor checks that affect claim validity for S82.146K.

Unspecified codes
Unspecified codes exist in the ICD-10-CM classification for circumstances when documentation in the medical record does not provide the level of detail needed to support reporting a more specific code. However, in the inpatient setting, there should generally be very limited and rare circumstances for which the laterality (right, left, bilateral) of a condition is unable to be documented and reported. The following pages contain the list of unspecified ICD-10-CM diagnosis codes for which there is a more specific code to identify laterality (right, left, bilateral) within that code family.

Present on Admission (POA)Billing

S82.146K is exempt from POA reporting on inpatient claims to general acute care hospitals. Review the other POA exempt codes in Injuries to the knee and lower leg (S80-S89).

Coding GuidelinesGuidance

The principles of multiple coding of injuries should be followed in coding fractures. Fractures of specified sites are coded individually by site, to the level of detail furnished by medical record content.

A fracture not indicated as open or closed should be coded to closed. A fracture not indicated whether displaced or not displaced should be coded to displaced.

Initial vs. Subsequent Encounter for Fractures

Traumatic fractures are coded using the appropriate 7th character for initial encounter (A, B, C) while the patient is receiving active treatment for the fracture. The appropriate 7th character for initial encounter should also be assigned for a patient who delayed seeking treatment for the fracture or nonunion.

Fractures are coded using the appropriate 7th character for subsequent care for encounters after the patient has completed active treatment of the fracture and is receiving routine care for the fracture during the healing or recovery phase.

Care for complications of surgical treatment for fracture repairs during the healing or recovery phase should be coded with the appropriate complication codes.

Care of complications of fractures, such as malunion and nonunion, should be reported with the appropriate 7th character for subsequent care with nonunion (K, M, N) or subsequent care with malunion (P, Q, R).

The open fracture designations in the assignment of the 7th character for fractures of the forearm, femur and lower leg, including ankle are based on the Gustilo open fracture classification. When the Gustilo classification type is not specified for an open fracture, the 7th character for open fracture type I or II should be assigned (B, E, H, M, Q).

Source: ICD-10-CM Official Guidelines for Coding and Reporting, FY 2026, published by CMS and the National Center for Health Statistics.

Clinical ClassificationClinical

AHRQ’s CCSR groups this code into broader clinical categories.

CCSR INJ042
Fracture of lower limb (except hip), subsequent encounter
Default principal diagnosis: inpatient Yes · outpatient Yes

Patient EducationClinical

Fractures

A fracture is a break in a bone. Fractures are usually caused by injuries. Since they can sometimes be serious, it's important to get medical care right away if you think you have a fracture.

The full article covers:

  • What is a fracture?
  • What are the different types of fractures?
  • What causes fractures?
  • What are the symptoms of a fracture?
  • How are fractures diagnosed?
  • What are the treatments for fractures?
  • Can fractures be prevented?

Read the full article at MedlinePlus

Courtesy of MedlinePlus, a service of the U.S. National Library of Medicine.

Convert S82.146K to ICD-9-CMHistory

The closest ICD-9-CM equivalents under the General Equivalence Mappings.

ICD-9-CM
733.82 Nonunion of fracture
Approximate The match is approximate rather than exact.

Code HistoryHistory

FY 2016AddedAdded to the ICD-10-CM code setEffective October 1, 2015, the first year of ICD-10-CM.
FY 2017–2025No changes
FY 2026CurrentCurrent code set, no changesEffective October 1, 2025 through September 30, 2026.

Questions About S82.146KOverview

Is S82.146K (Nondisplaced bicondylar fracture of unspecified tibia) a billable code?

Yes. This is a billable ICD-10-CM code, specific enough to report nondisplaced bicondylar fracture of unspecified tibia, subsequent encounter for closed fracture with nonunion on HIPAA-covered claims from October 1, 2025 through September 30, 2026.

What does the 7th character K in S82.146K mean?

The final character K reports a subsequent encounter where the nondisplaced bicondylar fracture of unspecified tibia has failed to heal, called a nonunion.

What MS-DRG does S82.146K group to?

When nondisplaced bicondylar fracture of unspecified tibia, subsequent encounter for closed fracture with nonunion is the principal diagnosis on an inpatient stay, it groups to MS-DRG 564, 565, 566, with relative weights from 0.7493 to 1.5436 depending on complications. Higher weights mean higher Medicare reimbursement.

Is S82.146K exempt from POA reporting?

Yes. CMS lists this code among those exempt from present on admission reporting, so hospitals do not assign a POA indicator for nondisplaced bicondylar fracture of unspecified tibia, subsequent encounter for closed fracture with nonunion on inpatient claims. The code appears in the Injuries to the knee and lower leg (S80-S89) range of the CMS exempt list.

What is the ICD-9 equivalent of S82.146K?

Under the General Equivalence Mappings, nondisplaced bicondylar fracture of unspecified tibia, subsequent encounter for closed fracture with nonunion converts to ICD-9-CM 733.82 (nonunion of fracture). The mapping is approximate, so confirm the match fits the documentation.