2026 ICD-10-CM Diagnosis Code S93.312ASubluxation of tarsal joint of left foot, initial encounter
S93.312A is a billable ICD-10-CM diagnosis code for subluxation of tarsal joint of left foot, 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. Coders also document this condition as subluxation of intertarsal joint of left foot. In AHRQ's Clinical Classifications Software (CCSR), this diagnosis falls under Dislocations, initial encounter.
Code Identity
Code Classification
Approximate SynonymsGuidance
Alternate terms and clinical phrases that map to this code.
- Subluxation of intertarsal joint of left foot
- Subluxation of joint of left foot
Coding GuidelinesGuidance
The appropriate 7th character is to be added to each code from block Dislocation and sprain of joints and ligaments at ankle, foot and toe level (S93). 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
Ankle Injuries and Disorders
Your ankle bone and the ends of your two lower leg bones make up the ankle joint. Your ligaments, which connect bones to one another, stabilize and support it. Your muscles and tendons move it.
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Convert S93.312A to ICD-9-CMHistory
The closest ICD-9-CM equivalents under the General Equivalence Mappings.
Code HistoryHistory
Questions About S93.312AOverview
Is S93.312A (Subluxation of tarsal joint of left foot) a billable code?
Yes. This is a billable ICD-10-CM code, specific enough to report subluxation of tarsal joint of left foot, initial encounter on HIPAA-covered claims from October 1, 2025 through September 30, 2026.
What does the 7th character A in S93.312A mean?
The final character A marks the initial encounter: use it while the patient is receiving active treatment for subluxation of tarsal joint of left foot, such as an emergency visit or first evaluation.
What MS-DRG does S93.312A group to?
When subluxation of tarsal joint of left foot, 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 S93.312A?
Under the General Equivalence Mappings, subluxation of tarsal joint of left foot, initial encounter converts to ICD-9-CM 838.02 (disloc midtarsal-closed). 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.
