Patient presents with complaints consistent with a possible head injury, diagnosed as Unspecified Head Injury (ICD-10 code S09.90XA).  Mechanism of injury is unclear and patient is unable to provide a complete history.  On examination, patient exhibits altered mental status, including confusion and disorientation.  Glasgow Coma Scale score is documented.  Neurological examination reveals [Insert specific neurological findings, e.g., normal pupillary response, intact extraocular movements, no focal neurological deficits].  There is no evidence of skull fracture on physical examination.  Imaging studies, including [Specify imaging ordered or completed, e.g., CT scan of the head without contrast, skull X-ray], were [Specify results, e.g., negative for acute intracranial hemorrhage, unremarkable].  Differential diagnosis includes concussion, contusion, and intracranial hemorrhage.  Due to the unclear mechanism and presentation, further investigation is warranted.  Patient is admitted for observation and neurological monitoring.  Treatment plan includes symptomatic management of headache and nausea with [Specify medications, e.g., acetaminophen, ondansetron].  Patient education provided on head injury symptoms, including post-concussive syndrome, and return to activity precautions.  Follow-up with neurology is scheduled.  Prognosis is guarded given the unspecified nature of the injury.  The medical decision making is of moderate complexity due to the diagnostic uncertainty.  This documentation supports the medical necessity for hospital admission and further evaluation.  Coding and billing reflect the evaluation and management services provided, as well as the diagnostic imaging and treatments administered.