I66 vs S06
I66 (Occlusion and stenosis of cerebral arteries, not resulting in cerebral infarction) compared with S06 (Intracranial injury), from the official CMS tabular data. Do not report these codes together: the official tabular list marks them Excludes1.
Can these codes be reported together?
No — do not report together. I66 carries an Excludes1 note covering S06: “traumatic intracranial hemorrhage (S06.-)”
Sole exception: when the two conditions are documented as unrelated to each other (ICD-10-CM Official Guidelines, Section I.A.12.a).
Side by side
| I66Occlusion and stenosis of cerebral arteries, not resulting in cerebral infarction | S06Intracranial injury | |
|---|---|---|
| Billing status | Non-billable header | Non-billable header Report instead: S06.0X0A, S06.0X0D, S06.0X0S, S06.0X1A, S06.0X1D |
| Classification | I00-I99 — Diseases of the Circulatory System (I00-I99) | S00-T88 — Injury, Poisoning and Certain Other Consequences of External Causes (S00-T88) |
| Definition | Occlusion and stenosis of cerebral arteries, not resulting in cerebral infarction is a non-billable ICD-10-CM category code (I66). | Intracranial injury is a non-billable ICD-10-CM category code (S06). |
| 7th character | — | The appropriate 7th character is to be added to each code from category S06, except as noted below |
| Includes | embolism of cerebral artery narrowing of cerebral artery obstruction (complete) (partial) of cerebral artery thrombosis of cerebral artery | traumatic brain injury injuries of ear injuries of eye injuries of face [any part] |
| Use additional code | code to identify presence of: alcohol abuse and dependence (F10.-) exposure to environmental tobacco smoke (Z77.22) | code, if applicable, to identify mild neurocognitive disorders due to known physiological condition (F06.7-) |
Derived from the official CMS ICD-10-CM tabular data (FY2026). Not billing advice; verify sequencing rules for the encounter. All data sources