2027 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 2027 ICD-10-CM dataset · Effective Oct 1, 2026 – Sep 30, 2027

I67.83 is a billable ICD-10-CM diagnosis code for posterior reversible encephalopathy syndrome. It is valid on HIPAA claims for fiscal year 2027 (October 1, 2026 through September 30, 2027) and groups to MS-DRG 70 through 72, 974 through 976. As a secondary diagnosis, it counts as a major complication or comorbidity (MCC) and places an inpatient stay in the highest severity level of its MS-DRG family. It does not count, however, when the principal diagnosis is one of 5 closely related codes. 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

Instructional NotesGuidance

Instructions from the official ICD-10-CM Tabular List that apply to I67.83: its own notes plus those printed at I67, block I60-I69, and Chapter 9. A note printed at a category, block or chapter applies to every code under it.

Applicable To

Conditions this code is used for: synonyms of the title or, for "other specified" codes, the conditions assigned to it. The list is not exhaustive.

  • PRES

Excludes1

Not coded here: the excluded code is never reported together with this one, unless the two conditions are unrelated.

From I67 Other cerebrovascular diseases applies to 17 codes
  • Occlusion and stenosis of cerebral artery causing cerebral infarction (I63.3-I63.5-)
  • Occlusion and stenosis of precerebral artery causing cerebral infarction (I63.2-)
From Block I60-I69 Cerebrovascular diseases applies to 410 codes
  • traumatic intracranial hemorrhage (S06.-)

Excludes2

Not included here: the excluded condition is not part of this code, but a patient may have both, so both codes may be reported.

From I67 Other cerebrovascular diseases applies to 17 codes
  • sequelae of the listed conditions (I69.8)
From Chapter 9 (I00-I99) Diseases of the circulatory system applies to 1,433 codes
  • certain conditions originating in the perinatal period (P04-P96)
  • certain infectious and parasitic diseases (A00-B99)
  • complications of pregnancy, childbirth and the puerperium (O00-O9A)
  • congenital malformations, deformations, and chromosomal abnormalities (Q00-Q99)
  • endocrine, nutritional and metabolic diseases (E00-E88)
  • injury, poisoning and certain other consequences of external causes (S00-T88)
  • neoplasms (C00-D49)
  • symptoms, signs and abnormal clinical and laboratory findings, not elsewhere classified (R00-R94)
  • systemic connective tissue disorders (M30-M36)
  • transient cerebral ischemic attacks and related syndromes (G45.-)

Use Additional Code

Add a second code, after this one, to fully describe the condition.

From Block I60-I69 Cerebrovascular diseases applies to 410 codes
  • code to identify presence of:
  • alcohol abuse and dependence (F10.-)
  • exposure to environmental tobacco smoke (Z77.22)
  • history of tobacco dependence (Z87.891)
  • hypertension (I10-I1A)
  • occupational exposure to environmental tobacco smoke (Z57.31)
  • tobacco dependence (F17.-)
  • tobacco use (Z72.0)

Source: CMS ICD-10-CM Tabular List. How to read instructional notes.

Index to Diseases and InjuriesGuidance

Alphabetical index entries that point to this code.

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

Clinical InformationClinical

  • Reversible Posterior Leukoencephalopathy Syndrome

    an acute or subacute reversible condition characterized by headaches, mental status changes, visual disturbances, and seizures associated with imaging findings of posterior leukoencephalopathy. it has been observed in association with hypertensive encephalopathy, eclampsia, and immunosuppressive and cytotoxic drug treatment.

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 2017–2026No changes
FY 2027CurrentCurrent code set, no changesEffective October 1, 2026 through September 30, 2027.

Questions About I67.83Overview

What is the ICD-10 code for posterior reversible encephalopathy syndrome?

The ICD-10-CM code for posterior reversible encephalopathy syndrome is I67.83 (sometimes written as I6783). It is billable on HIPAA-covered claims from October 1, 2026 through September 30, 2027.

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, 2026 through September 30, 2027.

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, 976, 72, 975, 70, 71, with relative weights from 0.7344 to 3.0488 depending on complications. Higher weights mean higher Medicare reimbursement.

Is I67.83 a CC or MCC?

CMS lists I67.83 as an MCC (major complication or comorbidity) for FY 2027. Reported as a secondary diagnosis, it places the inpatient stay in the highest-weighted DRG of its severity family. It does not count when the principal diagnosis is one of the 5 closely related codes in its exclusion list.

Can I67.83 be reported with a code from I63.2?

Not as a rule. The Excludes1 note at I67, which applies to I67.83, lists "Occlusion and stenosis of precerebral artery causing cerebral infarction (I63.2-)". An Excludes1 note means the excluded code is never reported together with this one; the only exception is when the two conditions are unrelated to each other (Official Guidelines, Section I.A.12.a).