No, everyone in the Netherlands who wants to go to a doctor must first make an appointment. You can make an appointment with the GC A (0 881 122 112), or during the registration hours at the AZC.  During the registration hour, the doctor's assistant will ask you what your symptoms are, and, if necessary, will make you an appointment with the practice-nurse or the familydoctor. A staff member working for the COA can tell you where you need to go, and at what time the registration hour is. You can also find this information at this website.

In case of an emergency, you can always call the GC A.