2026 ICD-10-CM Diagnosis Code M84.464APathological fracture, left fibula, initial encounter for fracture
M84.464A is a billable ICD-10-CM diagnosis code for pathological fracture, left fibula, initial encounter for fracture. 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 542 through 544. Coders also document this condition as pathological fracture of fibula. In AHRQ's Clinical Classifications Software (CCSR), this diagnosis falls under Pathological fracture, initial encounter.
Code Identity
Code Classification
Approximate SynonymsGuidance
Alternate terms and clinical phrases that map to this code.
- Pathological fracture of fibula
- Pathological fracture of left fibula
Clinical ClassificationClinical
AHRQ’s CCSR groups this code into broader clinical categories.
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 M84.464A to ICD-9-CMHistory
The closest ICD-9-CM equivalents under the General Equivalence Mappings.
Code HistoryHistory
Questions About M84.464AOverview
Is M84.464A (Pathological fracture, left fibula) a billable code?
Yes. This is a billable ICD-10-CM code, specific enough to report pathological fracture, left fibula, initial encounter for fracture on HIPAA-covered claims from October 1, 2025 through September 30, 2026.
What does the 7th character A in M84.464A mean?
The final character A marks the initial encounter: use it while the patient is receiving active treatment for pathological fracture, left fibula, such as an emergency visit or first evaluation.
What MS-DRG does M84.464A group to?
When pathological fracture, left fibula, initial encounter for fracture is the principal diagnosis on an inpatient stay, it groups to MS-DRG 542, 543, 544, with relative weights from 0.7546 to 1.7665 depending on complications. Higher weights mean higher Medicare reimbursement.
What is the ICD-9 equivalent of M84.464A?
Under the General Equivalence Mappings, pathological fracture, left fibula, initial encounter for fracture converts to ICD-9-CM 733.16 (path fx tibia fibula). 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.
