S06.821A Injury of left internal carotid artery, intracranial portion, not elsewhere classified with loss of consciousness of 30 minutes or less, initial encounter

Billable ICD-10-CM code, FY2026.

Built from S06.821 with 7th character A (initial encounter).

Applies from S06 Intracranial injury

Includes

• traumatic brain injury

Excludes1 (never code together)

• head injury NOS (S09.90)

Use additional code

• code, if applicable, to identify mild neurocognitive disorders due to known physiological condition (F06.7-)

Code also

• any associated:
• open wound of head (S01.-)
• skull fracture (S02.-)

7th character note

• The appropriate 7th character is to be added to each code from category S06, except as noted below

Notes

• 7th characters D and S do not apply to codes in category S06 with 6th character 7 - death due to brain injury prior to regaining consciousness, or 8 - death due to other cause prior to regaining consciousness.

7th character required

• A — initial encounter
• D — subsequent encounter
• S — sequela

Applies from S06.821 Injury of left internal carotid artery, intracranial portion, not elsewhere classified with loss of consciousness of 30 minutes or less

Applicable to

• Injury of left internal carotid artery, intracranial portion, not elsewhere classified with brief loss of consciousness

Risk adjustment (HCC)

• CMS-HCC V28: HCC 398 — Major Head Injury with Loss of Consciousness < 1 Hour or Unspecified
• CMS-HCC V22: HCC 167 — Major Head Injury
• ESRD V24: HCC 167

Code annotations containing back-references to S06.821A

Back-references to S06.8

• Type 1 Excludes: S06.9 Unspecified intracranial injury ("conditions classifiable to S06.0- to S06.8-code to specified intracranial injury")
• Type 1 Excludes: S15.0 Injury of carotid artery of neck ("injury of internal carotid artery, intracranial portion (S06.8)")

Back-references to S06

• Code First: F02 Dementia in other diseases classified elsewhere ("traumatic brain injury (S06.-)")
• Code First: F06.7 Mild neurocognitive disorder due to known physiological condition ("traumatic brain injury (S06.-)")
• Code First: F48.2 Pseudobulbar affect ("sequelae of traumatic intracranial injury (S06.-)")
• Type 1 Excludes: G31.84 Mild cognitive impairment of uncertain or unknown etiology ("cognitive impairment due to intracranial or head injury (S06.-)")
• Code Also: G96.00 Cerebrospinal fluid leak, unspecified ("head injury (S00-S09)")
• Code Also: G96.08 Other cranial cerebrospinal fluid leak ("head injury (S00 - S09)")
• Code Also: G96.09 Other spinal cerebrospinal fluid leak ("head injury (S00 - S09)")
• Type 1 Excludes: I69 Sequelae of cerebrovascular disease ("sequelae of traumatic intracranial injury (S06.-)")
• Type 1 Excludes: I69.8 Sequelae of other cerebrovascular diseases ("sequelae of traumatic intracranial injury (S06.-)")
• Type 1 Excludes: I69.9 Sequelae of unspecified cerebrovascular diseases ("sequelae of traumatic intracranial injury (S06.-)")
• Type 1 Excludes: P52 Intracranial nontraumatic hemorrhage of newborn ("intracranial hemorrhage due to other injury (S06.-)")
• Code First: R40.2 Coma ("intracranial injury (S06.-)")
• Code Also: S01 Open wound of head ("intracranial injury (S06.-)")
• Code Also: S02 Fracture of skull and facial bones ("any associated intracranial injury (S06.-)")
• Code First: S04 Injury of cranial nerve ("any associated intracranial injury (S06.-)")
• Use Additional: S07 Crushing injury of head ("intracranial injuries (S06.-)")
• Type 1 Excludes: S09.0 Injury of blood vessels of head, not elsewhere classified ("injury of cerebral blood vessels (S06.-)")

Nearby codes

• S06.820 Injury of left internal carotid artery, intracranial portion, not elsewhere classified without loss of consciousness
• S06.820A Injury of left internal carotid artery, intracranial portion, not elsewhere classified without loss of consciousness, initial encounter
• S06.820D Injury of left internal carotid artery, intracranial portion, not elsewhere classified without loss of consciousness, subsequent encounter
• S06.820S Injury of left internal carotid artery, intracranial portion, not elsewhere classified without loss of consciousness, sequela
• S06.821 Injury of left internal carotid artery, intracranial portion, not elsewhere classified with loss of consciousness of 30 minutes or less
• S06.821A Injury of left internal carotid artery, intracranial portion, not elsewhere classified with loss of consciousness of 30 minutes or less, initial encounter (this code)
• S06.821D Injury of left internal carotid artery, intracranial portion, not elsewhere classified with loss of consciousness of 30 minutes or less, subsequent encounter
• S06.821S Injury of left internal carotid artery, intracranial portion, not elsewhere classified with loss of consciousness of 30 minutes or less, sequela
• S06.822 Injury of left internal carotid artery, intracranial portion, not elsewhere classified with loss of consciousness of 31 minutes to 59 minutes
• S06.822A Injury of left internal carotid artery, intracranial portion, not elsewhere classified with loss of consciousness of 31 minutes to 59 minutes, initial encounter
• S06.822D Injury of left internal carotid artery, intracranial portion, not elsewhere classified with loss of consciousness of 31 minutes to 59 minutes, subsequent encounter