ICD-10 Code I99 – Other and unspecified disorders of circulatory system (2026): Diagnosis, Symptoms & Billing Guide
2026 ICD-10-CM Diagnosis Code I99 – Other and unspecified disorders of circulatory system
What it is
I99 is a nonspecific code for circulatory system disorders that do not fit a more exact diagnosis. Use it when the record documents a circulatory problem but does not identify the condition further.
Clinical signs
Clinical features vary; refer to documentation. Findings may include signs of impaired circulation, but the exact presentation depends on the underlying disorder and the body area involved.
When to use this code
Use I99 when the provider documents an unspecified disorder of the circulatory system and no more specific code is supported. It may also apply when the note describes a circulatory abnormality without enough detail for a precise diagnosis.
Review the record for the underlying cause, affected vessel, or anatomic site. If a more specific circulatory diagnosis is documented, code that condition instead of this residual category.
Do not use for
Do not use I99 when the chart supports a specific vascular, cardiac, or peripheral circulatory diagnosis. Check documentation if the condition is better described elsewhere in the ICD-10-CM system.
Coding tip
Use this code only after confirming that no more specific circulatory diagnosis is documented.