2026 ICD-10-CM Diagnosis Code I67.83Posterior reversible encephalopathy syndrome

ICD-10-CM Codes›I00–I99›I60-I69›I67

ICD-10-CM I67.83
CMSSource: CMS FY 2026 ICD-10-CM dataset · Effective Oct 1, 2025 – Sep 30, 2026

I67.83 is a billable ICD-10-CM diagnosis code for posterior reversible encephalopathy syndrome. It is valid on HIPAA claims for fiscal year 2026 (October 1, 2025 through September 30, 2026) and groups to MS-DRG 974 through 976. In AHRQ's Clinical Classifications Software (CCSR), this diagnosis falls under Other and ill-defined cerebrovascular disease.

Code Identity

ICD-10-CM Code
I67.83
Billable Status
Yes — Valid for Submission
Code Describes
Posterior reversible encephalopathy syndrome
Short Description
Posterior reversible encephalopathy syndrome
Same as the full description in the CMS dataset.
Parent Code
I67.8
Other specified cerebrovascular diseases

Code Classification

ChapterI00–I99Diseases of the circulatory system
SectionI60-I69Cerebrovascular diseases
CategoryI67Other cerebrovascular diseases
This CodeI67.83Posterior reversible encephalopathy syndrome

Approximate SynonymsGuidance

Alternate terms and clinical phrases that map to this code.

  • Posterior reversible encephalopathy syndrome

Tabular List NotesGuidance

Coding notes and annotation back-references applicable to this code.

Inclusion Terms

  • PRES

Index to Diseases and InjuriesGuidance

Alphabetical index entries that point to this code.

External Cause of Injuries IndexGuidance

References for this code in the External Cause of Injuries Index.

    • PRES(posterior reversible encephalopathy syndrome)
    • Syndrome
      • posterior
        • reversible encephalopathy (PRES)

Clinical ClassificationClinical

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

CCSR CIR024
Other and ill-defined cerebrovascular disease
Default principal diagnosis: inpatient Yes · outpatient Yes

Patient EducationClinical

Brain Diseases

Your brain is the control center of your body. It controls your thoughts, memory, speech, and movement. It regulates the function of many organs. It's part of your nervous system, which also includes your spinal cord and peripheral nerves. The nervous system sends signals between your brain and the rest of the body.

Read the full article at MedlinePlus

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

Convert I67.83 to ICD-9-CMHistory

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

ICD-9-CM
348.39 Encephalopathy NEC
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 I67.83Overview

Is I67.83 (Other specified cerebrovascular diseases) a billable code?

Yes. This is a billable ICD-10-CM code, specific enough to report posterior reversible encephalopathy syndrome on HIPAA-covered claims from October 1, 2025 through September 30, 2026.

What MS-DRG does I67.83 group to?

When posterior reversible encephalopathy syndrome is the principal diagnosis on an inpatient stay, it groups to MS-DRG 974, 975, 976, with relative weights from 0.8945 to 2.8860 depending on complications. Higher weights mean higher Medicare reimbursement.

What is the ICD-9 equivalent of I67.83?

Under the General Equivalence Mappings, posterior reversible encephalopathy syndrome converts to ICD-9-CM 348.39 (encephalopathy NEC). 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.