Lawful permanent residents can apply for U.S. citizenship after five years of acquiring permanent resident status. The waiting period is only three years if married to a United States citizen. U.S. citizens can have tax, employment, and other benefits. Those who qualify will have the required duration of physical presence in the United States, Good Moral Character, English language competency (if applicable), and U.S. history and civics knowledge. There are certain circumstances when eligible permanent residents should not apply for American citizenship because doing so can result in complications and potentially, deportation.