2026 ICD-10-CM Diagnosis Code G08Intracranial and intraspinal phlebitis and thrombophlebitis

ICD-10-CM CodesG00–G99G00-G09G08

ICD-10-CM G08
CMSSource: CMS FY 2026 ICD-10-CM dataset · Effective Oct 1, 2025 – Sep 30, 2026

G08 is a billable ICD-10-CM diagnosis code for intracranial and intraspinal phlebitis and thrombophlebitis. It is valid on HIPAA claims for fiscal year 2026 (October 1, 2025 through September 30, 2026). In AHRQ's Clinical Classifications Software (CCSR), this diagnosis falls under Other nervous system disorders (neither hereditary nor degenerative).

Code Identity

ICD-10-CM Code
G08
Billable Status
Yes — Valid for Submission
Code Describes
Intracranial and intraspinal phlebitis and thrombophlebitis
Chapter
G00-G09
Inflammatory diseases of the central nervous system

Code Classification

ChapterG00–G99Diseases of the nervous system
SectionG00-G09Inflammatory diseases of the central nervous system
CategoryG08Intracranial and intraspinal phlebitis and thrombophlebitis
This CodeG08Intracranial and intraspinal phlebitis and thrombophlebitis

Approximate SynonymsGuidance

Alternate terms and clinical phrases that map to this code.

  • Cavernous sinus syndrome
  • Cerebral venous sinus thrombosis
  • Cerebral venous thrombosis of cortical vein
  • Cerebral venous thrombosis of sigmoid sinus
  • Cerebral venous thrombosis of straight sinus
  • Embolism of basilar sinus
  • Embolism of cavernous venous sinus
  • Embolism of inferior sagittal sinus
  • Embolism of intracranial venous sinus
  • Embolism of lateral venous sinus
  • Endophlebitis
  • Endophlebitis of basilar sinus
  • Endophlebitis of cavernous venous sinus
  • Endophlebitis of inferior sagittal sinus
  • Endophlebitis of intracranial venous sinus
  • Endophlebitis of lateral venous sinus
  • Endophlebitis of superior sagittal sinus
  • Endophlebitis of torcular Herophili
  • Intracranial septic embolism
  • Intracranial septic thrombophlebitis
  • Intracranial thrombophlebitis
  • Intracranial venous septic embolism
  • Non-pyogenic venous sinus thrombosis
  • Phlebitis cavernous sinus
  • Phlebitis of basilar sinus
  • Phlebitis of inferior sagittal sinus
  • Phlebitis of intracranial venous sinus
  • Phlebitis of lateral venous sinus
  • Phlebitis of superior sagittal sinus
  • Phlebitis of torcular Herophili
  • Septic thrombophlebitis
  • Septic thrombophlebitis of cavernous sinus
  • Septic thrombophlebitis of cortical vein
  • Septic thrombophlebitis of great cerebral vein
  • Septic thrombophlebitis of lateral sinus
  • Septic thrombophlebitis of sagittal sinus
  • Septic thrombophlebitis of sigmoid sinus
  • Septic thrombophlebitis of straight sinus
  • Thrombophlebitis lateral venous sinus
  • Thrombophlebitis of basal vein of Rosenthal
  • Thrombophlebitis of basilar sinus
  • Thrombophlebitis of cavernous sinus
  • Thrombophlebitis of central nervous system venous sinuses
  • Thrombophlebitis of cerebral vein
  • Thrombophlebitis of inferior sagittal sinus
  • Thrombophlebitis of internal cerebral vein
  • Thrombophlebitis of intracranial venous sinus
  • Thrombophlebitis of sigmoid sinus
  • Thrombophlebitis of straight sinus
  • Thrombophlebitis of superior anastomotic vein
  • Thrombophlebitis of superior sagittal sinus
  • Thrombophlebitis of torcular Herophili
  • Thrombosis of basal vein
  • Thrombosis of basilar sinus
  • Thrombosis of cavernous venous sinus
  • Thrombosis of cerebral medullary veins
  • Thrombosis of cerebral venous sinus due to and following surgical procedure
  • Thrombosis of inferior sagittal sinus
  • Thrombosis of lateral venous sinus
  • Thrombosis of superior anastomotic vein
  • Thrombosis of superior sagittal sinus
  • Thrombosis of torcular Herophili

Tabular List NotesGuidance

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

Inclusion Terms

  • Septic embolism of intracranial or intraspinal venous sinuses and veins
  • Septic endophlebitis of intracranial or intraspinal venous sinuses and veins
  • Septic phlebitis of intracranial or intraspinal venous sinuses and veins
  • Septic thrombophlebitis of intracranial or intraspinal venous sinuses and veins
  • Septic thrombosis of intracranial or intraspinal venous sinuses and veins

Type 1 Excludes

  • intracranial phlebitis and thrombophlebitis complicating:
  • abortion, ectopic or molar pregnancy O00 O07 O08.7
  • pregnancy, childbirth and the puerperium O22.5 O87.3
  • nonpyogenic intracranial phlebitis and thrombophlebitis I67.6

Type 2 Excludes

  • intracranial phlebitis and thrombophlebitis complicating nonpyogenic intraspinal phlebitis and thrombophlebitis G95.1

Index to Diseases and InjuriesGuidance

External Cause of Injuries IndexGuidance

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

    • Embolism(multiple) (paradoxical)
      • intracranial
        • venous sinus (any)
    • Embolism(multiple) (paradoxical)
      • intraspinal venous sinuses or veins
    • Embolism(multiple) (paradoxical)
      • venous sinus
    • Inflammation, inflamed, inflammatory(with exudation)
      • vein
        • intracranial or intraspinal (septic)
    • Phlebitis(infective) (pyemic) (septic) (suppurative)
      • intracranial (venous) sinus (any)
    • Phlebitis(infective) (pyemic) (septic) (suppurative)
      • intraspinal venous sinuses and veins
    • Thrombophlebitis
      • cavernous (venous) sinus
    • Thrombophlebitis
      • cerebral (sinus) (vein)
    • Thrombophlebitis
      • intracranial venous sinus (any)
    • Thrombophlebitis
      • intraspinal venous sinuses and veins
    • Thrombophlebitis
      • lateral (venous) sinus
    • Thrombophlebitis
      • longitudinal (venous) sinus
    • Thrombophlebitis
      • sinus (intracranial)
    • Thrombosis, thrombotic(bland) (multiple) (progressive) (silent) (vessel)
      • intracranial (arterial)
        • venous sinus (any)
    • Thrombosis, thrombotic(bland) (multiple) (progressive) (silent) (vessel)
      • intraspinal venous sinuses and veins

Clinical ClassificationClinical

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

CCSR NVS020
Other nervous system disorders (neither hereditary nor degenerative)
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 G08 to ICD-9-CMHistory

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

ICD-9-CM
325 Phlebitis intrcran sinus
Exact Match The mapping is direct, with no qualifiers.

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 G08Overview

Is G08 (Intracranial and intraspinal phlebitis and thrombophlebitis) a billable code?

Yes. This is a billable ICD-10-CM code, specific enough to report intracranial and intraspinal phlebitis and thrombophlebitis on HIPAA-covered claims from October 1, 2025 through September 30, 2026.

What is the ICD-9 equivalent of G08?

Under the General Equivalence Mappings, intracranial and intraspinal phlebitis and thrombophlebitis converts to ICD-9-CM 325 (phlebitis intrcran sinus). The mapping is a direct match.

Footnotes

[1] Chronic - a chronic condition code indicates a condition lasting 12 months or longer and its effect on the patient based on one or both of the following criteria:

  • The condition results in the need for ongoing intervention with medical products,treatment, services, and special equipment
  • The condition places limitations on self-care, independent living, and social interactions.