In order to naturalize as a citizen of the United States, the initial requirement for all applicants is to be a Permanent Resident (i.e. have a Green Card). Depending on your situation, you’ll need to have been a permanent resident for at least three to five years prior to applying for citizenship. In addition, you must be at least 18 years old when you file your naturalization application; be able to speak, read and write basic English; and be a person of good moral character. For many of the requirements, certain exceptions apply and it’s useful to consult with an attorney near you to see whether you qualify for requirement exemptions.