S06.366ATraumatic hemorrhage of cerebrum, unspecified, with loss of consciousness greater than 24 hours without return to pre-existing conscious level with patient surviving, initial encounter

S06.366A is the ICD-10-CM diagnosis code for traumatic hemorrhage of cerebrum, unspecified, with loss of consciousness greater than 24 hours without return to pre-existing conscious level with patient surviving, initial encounter. It belongs to category S06 (intracranial injury), block S00-S09 (injuries to the head) and chapter 19 (injury, poisoning and certain other consequences of external causes). It is billable, so it can be reported on its own for dates of service from October 1, 2026 through September 30, 2027.

The 7th character "A" means initial encounter: use it while the patient is receiving active treatment for the condition.

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

As a secondary diagnosis it is an MCC (major complication or comorbidity), which can move an inpatient stay into the highest-paying "with MCC" MS-DRG of its family, unless the principal diagnosis excludes it.

In MS-DRG v44.0, it is part of the grouping logic for DRG 020 (Intracranial Vascular Procedures with Principal Diagnosis Hemorrhage with MCC, relative weight 7.9629), DRG 021 (Intracranial Vascular Procedures with Principal Diagnosis Hemorrhage with CC, relative weight 5.4726), DRG 022 (Intracranial Vascular Procedures with Principal Diagnosis Hemorrhage without CC/MCC, relative weight 3.3534), DRG 023 (Craniotomy with Major Device Implant or Acute Complex CNS Principal Diagnosis with MCC or Antineoplastic Implant or Epilepsy with Neurostimulator, relative weight 5.7444), DRG 024 (Craniotomy with Major Device Implant or Acute Complex CNS Principal Diagnosis without MCC, relative weight 3.9708), DRG 082 (Traumatic Stupor and Coma >1 Hour with MCC, relative weight 2.2928) and 5 more, in MDC 01 (Diseases and Disorders of the Nervous System) and MDC 24 (Multiple Significant Trauma), as a principal or secondary diagnosis. The DRG a claim lands in depends on the principal diagnosis, procedures and any CC/MCC secondary diagnoses.

It has been part of ICD-10-CM since the code set took effect on October 1, 2015 and hasn't changed since.

Before ICD-10, this condition was coded in ICD-9-CM as 853.05 (other and unspecified intracranial hemorrhage following injury without mention of open intracranial wound, with prolonged [more than 24 hours] loss of consciousness without return to pre-existing conscious level).