If you are a resident alien for the entire year, you must file a tax return following the same rules that apply to U.S. citizens. Use the forms discussed in this publication. If you are a nonresident alien, the rules and tax forms that apply to you are different from those that apply to U.S. citizens and resident aliens. See Publication 519 to find out if U.S. income tax laws apply to you and which forms you should file. If you were a resident alien for part of the tax year and a nonresident alien for the rest of the year, you are a dual-status taxpayer.
Different rules apply for each part of the year.
For information on dual-status taxpayers, see Publication 519 . Even if you do not have to file, you should file a federal income tax return to get money back if any of the following conditions apply. You had income tax withheld from your pay. You qualify for the earned income credit. See chapter 37 for more information.