Visiting a USCIS field office is not required in many situations because the federal agency’s website provides information and tools to learn about immigration and follow the progress of a case. Here are three of these online resources:
Service locators: The website helps you find a variety of services. You can search for the location of a field office by providing your zip code. Similarly, you can search for authorized doctors by zip code or address. (The medical exam for Green Card applicants is performed by a USCIS-designated doctor. Another locator tool the site has is for finding English and Citizenship prep classes.
Case status: If you’ve submitted a request, application, or petition, you can check its status online. For this, you need to provide the identification number given to you when you applied.
Calculators: The tools section also has a calculator for form filing fees and one for early filing of the N-400.