ICD-10-CM 2027
ICD-10 code for PRES
Posterior reversible encephalopathy syndrome
From the official ICD-10-CM alphabetic index entry “PRES (posterior reversible encephalopathy syndrome)”. Page updated September 29, 2026.
About coding PRES
The ICD-10-CM code for PRES is I67.83 (Posterior reversible encephalopathy syndrome).
Within I67.8 (other specified cerebrovascular diseases), I67.83 is specifically for posterior reversible encephalopathy syndrome. Related codes cover acute cerebrovascular insufficiency (I67.81), cerebral ischemia (I67.82), cerebral vasospasm and vasoconstriction (I67.84), hereditary cerebrovascular diseases (I67.85) and other cerebrovascular disease (I67.89).
As a secondary diagnosis it is an MCC (major complication or comorbidity), which can move an inpatient stay into the highest-paying "with MCC" MS-DRG of its family, unless the principal diagnosis excludes it.
In MS-DRG v44.0, it is part of the grouping logic for DRG 070 (Other Cerebrovascular Disorders with MCC, relative weight 1.6093), DRG 071 (Other Cerebrovascular Disorders with CC, relative weight 1.0177), DRG 072 (Other Cerebrovascular Disorders without CC/MCC, relative weight 0.7348), DRG 974 (HIV with Major Related Condition with MCC, relative weight 3.0506), DRG 975 (HIV with Major Related Condition with CC, relative weight 1.3252) and DRG 976 (HIV with Major Related Condition without CC/MCC, relative weight 0.8124), in MDC 01 (Diseases and Disorders of the Nervous System) and MDC 25 (Human Immunodeficiency Virus Infections), as a principal or secondary diagnosis. The DRG a claim lands in depends on the principal diagnosis, procedures and any CC/MCC secondary diagnoses.
Common questions about PRES ICD-10 codes
What is the ICD-10 code for PRES?
- I67.83 — Posterior reversible encephalopathy syndrome.
Is I67.83 billable?
- Yes. I67.83 is a billable/specific ICD-10-CM code valid for FY2027 (October 1, 2026 – September 30, 2027).
Can I67.83 be used as a principal diagnosis?
- Yes. The Medicare Code Editor doesn't restrict I67.83 as a principal diagnosis.
Is I67.83 a CC or MCC?
- I67.83 is an MCC (major complication or comorbidity) under MS-DRG v44.0, unless excluded by the principal diagnosis.