2026 ICD-10-CM Diagnosis Code S83.145ALateral dislocation of proximal end of tibia, left knee, initial encounter

ICD-10-CM CodesS00–T88S80-S89S83

ICD-10-CM S83.145A
CMSSource: CMS FY 2026 ICD-10-CM dataset · Effective Oct 1, 2025 – Sep 30, 2026

S83.145A is a billable ICD-10-CM diagnosis code for lateral dislocation of proximal end of tibia, left knee, initial encounter. The 7th character A marks it as an initial encounter code, used while the patient is receiving active treatment. It is valid on HIPAA claims for fiscal year 2026 (October 1, 2025 through September 30, 2026) and groups to MS-DRG 562 through 563, 963 through 965. In AHRQ's Clinical Classifications Software (CCSR), this diagnosis falls under Dislocations, initial encounter.

Code Identity

ICD-10-CM Code
S83.145A
Billable Status
Yes — Valid for Submission
Code Describes
Lateral dislocation of proximal end of tibia, left knee, initial encounter
Short Description
Lateral disloc of proximal end of tibia, left knee, init
Parent Code
Lateral dislocation of proximal end of tibia, left knee

Code Classification

ChapterS00–T88Injury, poisoning and certain other consequences of external causes
SectionS80-S89Injuries to the knee and lower leg
CategoryS83Dislocation and sprain of joints and ligaments of knee
This CodeS83.145ALateral dislocation of proximal end of tibia, left knee, initial encounter

Coding GuidelinesGuidance

The appropriate 7th character is to be added to each code from block Dislocation and sprain of joints and ligaments of knee (S83). Use the following options for the applicable episode of care:

  • A - initial encounter
  • D - subsequent encounter
  • S - sequela

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 INJ007
Dislocations, initial encounter
Default principal diagnosis: inpatient Yes · outpatient Yes

Patient EducationClinical

Dislocations

Dislocations are joint injuries that force the ends of your bones out of position. The cause is often a fall or a blow, sometimes from playing a contact sport. You can dislocate your ankles, knees, shoulders, hips, elbows and jaw. You can also dislocate your finger and toe joints.

Read the full article at MedlinePlus

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

Convert S83.145A to ICD-9-CMHistory

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

ICD-9-CM
836.54 Lat disloc prox tibia-cl
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 S83.145AOverview

Is S83.145A (Lateral dislocation of proximal end of tibia, left knee) a billable code?

Yes. This is a billable ICD-10-CM code, specific enough to report lateral dislocation of proximal end of tibia, left knee, initial encounter on HIPAA-covered claims from October 1, 2025 through September 30, 2026.

What does the 7th character A in S83.145A mean?

The final character A marks the initial encounter: use it while the patient is receiving active treatment for lateral dislocation of proximal end of tibia, left knee, such as an emergency visit or first evaluation.

What MS-DRG does S83.145A group to?

When lateral dislocation of proximal end of tibia, left knee, initial encounter is the principal diagnosis on an inpatient stay, it groups to MS-DRG 562, 563, 963, 964, 965, with relative weights from 0.8955 to 2.7338 depending on complications. Higher weights mean higher Medicare reimbursement.

What is the ICD-9 equivalent of S83.145A?

Under the General Equivalence Mappings, lateral dislocation of proximal end of tibia, left knee, initial encounter converts to ICD-9-CM 836.54 (lat disloc prox tibia-cl). The mapping is approximate, so confirm the match fits the documentation.

Footnotes

[1] Not chronic - A diagnosis code that does not fit the criteria for chronic condition (duration, ongoing medical treatment, and limitations) is considered not chronic. Some codes designated as not chronic are acute conditions. Other diagnosis codes that indicate a possible chronic condition, but for which the duration of the illness is not specified in the code description (i.e., we do not know the condition has lasted 12 months or longer) also are considered not chronic.