Naturalization is the path by which a permanent resident can obtain U.S. citizenship, and its starting point is Form N-400. Below are the requirements to apply, how much it costs, what the test is like, and the stages that make up the process. What Is Form N-400 Form N-400 (Application for Naturalization) is the document with which a permanent resident (green card holder) applies to become a U.S. citizen. It is filed with the U.S. Citizenship and Immigration Services (USCIS), online or on paper, and is the formal beginning of the naturalization process. ¿How much does it cost? The N-400 fee depends on how it is filed: - USD 710 if filed online - USD 760 if filed on paper There is also a reduced fee (USD 380) for those who meet certain income requirements, and exemptions for cases such as members of the Armed Forces. The main requirements to obtain U.S. citizenship To apply for citizenship, in general you must meet: - Be a permanent resident and be 18 years of age or older - Have lived as a permanent resident for at least 5 years (or 3 years if married to a U.S. citizen and the conditions are met) - Meet the continuous residence and physical presence requirements in the country (in general, having been present for half of the required period) - Have lived for at least 3 months in the state or district where the application is filed - Demonstrate good moral character - Pass an English test and a civics test The test: English and civics The naturalization test has two parts: - English: speaking, reading, and writing basic English are assessed - Civics: questions about the history and government of the United States For applications filed starting on October 20, 2025, the 2025 version of the civics test applies: a total of 128 questions are studied, of which the officer asks 20 during the interview, and 12 must be answered correctly to pass. Those who filed their application before that date continue taking the previous version (2008): 100 study questions, 10 in the interview, and 6 correct answers to pass. What determines which test each person takes is the filing date of the N-400, not the interview date. In addition, there are exceptions based on age and length of residence (such as the rule known as “65/20”) and exemptions for certain conditions. The steps in the process Broadly speaking, the naturalization path includes: - Confirm that the requirements are met - Gather supporting documentation - File Form N-400 (online or by mail) and pay the fee - Receive the receipt notice - Attend the biometrics appointment (photo, fingerprints, and signature) - Attend the interview, where the English and civics tests are administered - Receive the decision on the application - If approved, attend the oath ceremony, the moment when citizenship is officially obtained The total time varies depending on the office, but it usually falls in the range of several months to around one year.