2026 ICD-10-CM Diagnosis Code S83.231AComplex tear of medial meniscus, current injury, right knee, initial encounter
S83.231A is a billable ICD-10-CM diagnosis code for complex tear of medial meniscus, current injury, right 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 Sprains and strains, initial encounter.
Code Identity
Code Classification
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.
Patient EducationClinical
Cartilage Disorders
Cartilage is the tough but flexible tissue that covers the ends of your bones at a joint. It also gives shape and support to other parts of your body, such as your ears, nose and windpipe. Healthy cartilage helps you move by allowing your bones to glide over each other.
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Convert S83.231A to ICD-9-CMHistory
The closest ICD-9-CM equivalents under the General Equivalence Mappings.
Code HistoryHistory
Questions About S83.231AOverview
Is S83.231A (Complex tear of medial meniscus, current injury, right knee) a billable code?
Yes. This is a billable ICD-10-CM code, specific enough to report complex tear of medial meniscus, current injury, right knee, initial encounter on HIPAA-covered claims from October 1, 2025 through September 30, 2026.
What does the 7th character A in S83.231A mean?
The final character A marks the initial encounter: use it while the patient is receiving active treatment for complex tear of medial meniscus, current injury, right knee, such as an emergency visit or first evaluation.
What MS-DRG does S83.231A group to?
When complex tear of medial meniscus, current injury, right 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 S83.231A?
Under the General Equivalence Mappings, complex tear of medial meniscus, current injury, right knee, initial encounter converts to ICD-9-CM 836.0 (tear med menisc knee-cur). 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.
