Introduction If you are a citizen or resident of the United States and your gross income for the tax year is at least the amount shown for your status under Filing Requirements, later, you must file a 2001 federal income tax return. This is true even if no tax is due. Gross income is explained later. If you do not meet the gross income requirement, you may still need to file a tax return if any of the following apply. You have net earnings of $400 or more from self-employment. You are entitled to certain credits. You are entitled to a complete refund of tax withheld. If you are a "qualified" farmer, defined later, you are subject to the special rules covered in this chapter for paying estimated tax and filing your tax return. This chapter also includes information about various forms and returns you may need to file.