Do I need to give my insurance information in the emergency room?

Yes, when you go to any Emergency Department (ED) you will be asked for insurance information and you should give it if you have it available.  That said, there is no law that requires you to give the insurance information.  In addition, there is a Federal law (called "EMTALA") that requires the ED to "stabilize" your condition and treat it within the capabilities of the hospital.  In other words, an ED cannot turn you away simply because you lack health insurance.  They must examine you and treat you to the extent that you are "medically stable."  The devil is in the details, as in all laws, and EMTALA does not specify what it means to stabilize someone.  In general, you must be treated to the extent that you can be safely discharged to your own care or the care of a responsible lay person, and with a reasonable follow-up recommendation for your condition if warranted.