When using 434.91 make sure you take all of the specifics into account. When a doctor says that a patient has had a stroke make sure that you know all of the details of the situation or else some procedures can be hard to justify and therefore your medical billing reimbursement may be denied. In the past for diagnosis of a stroke the ICD-9 index listed 436, which is acute but ill defined cerebrovascular disease, as the code to use. Now the index has code 434.91 as the code to use. This is cerebral artery occlusion, unspecified with cerebral infarction. The new ICD-9 index automatically translates a doctors diagnosis of …