In order to be eligible for U.S. citizenship, you must:

• Be at least 18 years old.
• Have been a Lawful Permanent Resident (green card holder) for at least 5 years, OR be a Lawful Permanent Resident for at least 3 years if married to and living with your U.S. Citizen spouse. Other exceptions apply to members of U.S military, diplomats and their spouses.
• Have been physically present in the United States for at least half of the period of permanent residency, not have traveled outside the U.S for longer than that. For a five year residency, this means no more than 2.5 years or 30 months. 
• Have been continuously in the U.S, and not have left the U.S. for long periods of time during the past 5 years (i.e you may be at risk if you left the U.S. 6 months at a time or longer, and you are ineligible if you left the U.S. for 1 year or longer).
• Have residence in the district where you are applying for at least 3 months.
• Be a person of good moral character.
• Be able to speak, read, write and understand basic English (age and/or medical exemptions may apply for those who qualify).
• Have basic knowledge of United States history, government, and civics
• Be willing to take an Oath of Allegiance to the United States.