Question: Which diagnosis code should we report when a traumatic brain injury causes cognitive deficits? Alaska Subscriber Answer: The ICD-9 alphabetic index directs coders to review 294.9 (Unspecified persistent mental disorders due to conditions classified elsewhere) for the listing "Disorder, cognitive," and ICD-9 lists "Cognitive disorder NOS" as an acceptable term under the code in the tabular section. However, some coders are rightfully concerned that its unspecified nature can cause denials. What it is: "Cognitive deficit" means the patient has difficulties in reasoning, judgment, intuition, and memory, and lack of awareness and insight. "Cognitive impairment," on the other hand, is a deficiency in ability to think, perceive, reason, or remember resulting in loss of ability to attend to one's daily living needs. Cognitive deficits may be congenital or caused by environmental factors such as brain injuries, neurological disorders, or mental illness. Best bet: Educate your neurologist on the importance of clearly documenting what the patient has specific problems performing -- such as difficulty with perception or memory, impaired judgment, inattentiveness, impulsiveness, or impairment of speech and language. Option 1: If your neurologist documents a specific problem due to brain damage, you may be able to classify the condition using a code from the 310.1x (Specific nonpsychotic mental disorders due to brain damage) range. Even though these codes are in the mental disorders section, the subsection 310.x is clearly for nonpsychotic mental disorders due to brain damage. Option 2: You may opt to use 294.8 (Other persistent mental disorders due to conditions classified elsewhere) if your neurologist's documentation supports a more specified diagnosis than the "unspecified" for 294.9. When the neurologist's documentation supports it, you also should report a late effect diagnosis code. For example reporting 907.0 (Late effect of intracranial injury without mention of skull fracture) as a secondary ICD-9 code for a patient with cognitive deficits due to a previous closed head injury. This will help more clearly depict that the patient's cognitive deficit was due to brain injury rather than associated with a mental illness.