The filing status you use when you file your return determines the tax rates that will apply (1.2) to your taxable income. Filing status also determines the standard deduction you may claim (13.1) if you do not itemize deductions and your ability to claim certain other deductions, credits, and exclusions.
This chapter explains the five different filing statuses: single, married filing jointly, married filing separately, head of household, and qualifying widow(er). If you are married, filing a joint return is generally advantageous, but there are exceptions discussed in 1.3. If you are unmarried and are supporting a child who lives with you, you may qualify as a head of household (1.12), which will enable you to use more favorable tax rates than those allowed for single ...