Question: We had a patient come in who had an eye injury he had incurred at work, but the situation is a little bit foggy. He works for a company based in Illinois, but the accident happened in Indiana, so we aren’t sure which state’s billing rules we should follow. Can you advise? Indiana Subscriber Answer: You should follow the rules and fee schedule of the state in which the worker’s comp claim was originally filed. This may or may not be the same as the patient’s current state of residence. The state where the claim was filed will have jurisdiction over the claim -- the only exception is workers’ comp for federal employees, which has nationwide rules. In addition, you should be aware that not every state uses current-year CPT® codes. You may get denials or experience delays if you’re using new codes and your workers’ comp carrier isn’t up-to-date. Your best bet is to ask your state carrier or check the website for the appropriate CPT® codes to use. And, it’s important to use additional diagnosis codes to reflect the external cause of the injury. Of course these codes will never be the primary diagnoses, but they’re important because they complete the picture of the patient’s injury, treatment and claim. Patients may have more than one workers’ comp claim open and in the system. An external cause of injury code (V00-Y99) can help the payer differentiate between the claims and get them paid faster.