ICD-10 Code G08 – Intracranial and intraspinal phlebitis and thrombophlebitis (2026): Diagnosis, Symptoms & Billing Guide
2026 ICD-10-CM Diagnosis Code G08 – Intracranial and intraspinal phlebitis and thrombophlebitis
What it is
G08 identifies inflammation and clotting in veins within the skull or spinal canal. Use it when the record documents intracranial or intraspinal venous thrombophlebitis, not arterial disease.
Clinical signs
Clinical features vary; refer to documentation. Commonly recorded findings include neurologic symptoms, headache, fever, or signs of venous sinus involvement, but the diagnosis should be supported by imaging or specialist assessment.
When to use this code
Use G08 when the provider clearly documents phlebitis or thrombophlebitis affecting intracranial or intraspinal veins. It may appear with cerebral venous sinus thrombosis, spinal venous thrombosis, or related infectious complications if the note supports the diagnosis.
If the chart only mentions thrombosis without specifying the anatomic site, check documentation before coding. Assign the code only when the location and venous nature are explicit.
Do not use for
Do not use G08 for arterial stroke, nonspecific venous thrombosis, or superficial thrombophlebitis outside the central nervous system. Check documentation if the record is unclear.
Coding tip
Confirm both the intracranial or intraspinal location and the thrombophlebitis wording before assigning G08.