In California at least, you can not bill the patient or their private insurance if it's a known worker's comp case. They would need to go where the carrier authorizes them to go. If it's the initial treatment, the employer should have a directive as to where they're supposed to go for initial treatment. If it's a "hospital" do they have a choice to take comp or not? Again, in California, the initial visit is ALWAYS paid for, so they would get paid, but follow up treatment would have to be authorized.