If you are interested in becoming a US citizen, you must meet several requirements. Depending on your situation, there are different requirements that may apply to you, including the following. Be at least 18 years old at the time of filing your application. Be a permanent resident for at least five years. If you are married to a US citizen, this requirement may change to three years. Have lived within the state or US CIS district with jurisdiction over the applicant's place of residence for at least three months prior to the date of filing the application. You will need to demonstrate continuous residence in the United States. Continuous residence means that as a permanent resident, you have not left the United States for a long period of time. If you leave the United States for too long, you may interrupt your continuous residence. Physical presence in the United States. You will also need to demonstrate physical presence in the United States. This means that you need to be physically present in the country for at least 30 months out of the five years preceding the date of filing your application. Other requirements include being able to read, write, and speak English and having a basic understanding of US history and government. Some people who apply for naturalization may not have to meet the English requirement because of their age and the length of time they have lived in the United States as a permanent resident. In addition, you must demonstrate a knowledge and understanding of the fundamentals of the history and of the principles and form of government of the United States. Moral character. You also need to be a person of good moral character in order to become a naturalized US citizen. Committing certain crimes may cause you to be inaligible for naturalization. Oath of allegiance. Finally, to become a US citizen, you will have to take the oath of allegiance. All applicants for naturalization must be willing to support and defend the United States' inner constitution. In fact, it is not until you take the oath of allegiance that you actually become a US citizen. Please note that you are required to reside in the United States while your application is pending. Remember, these are only general requirements. For more detailed information, contact US citizenship and immigration services, US, CIS, online or bifone at 1-800-375-5283. This video was produced by USA.gov in collaboration with US citizenship and immigration services.