Medical Billing for Emergency Procedures Knowing when to use code 90782 in emergency department procedures can help with your medical billing reimbursements. For example, if a doctor examines a patient in the ED for an injury, and injects a preventative tetanus toxoid, your first instinct might be to use 90782 as a modifier for this procedure. But you would not receive a medical billing reimbursement because the incident to provision does not apply in the emergency department so you would not be able to justify having the doctor administer this injection. There would be no way to justify the medical necessity of such a shot. However, when you are in …