The filing status you use when you file your return determines the tax that will apply to your taxable income.
Filing status also determines the standard deduction you may claim if you do not itimize deductions and your ability to claim certain other deductions, credits, and exclusions.
•For federal tax purposes, a marriage means only a legal union between a man and a woman as husband and wife.
If you are divorced during the year under a final decree of divorce or separate maintenance, you are treated as unmarried for that whole year, assuming you have not remarried before the end of the year. For the year of the divorce, file as a single person unless you care for a child or parent and qualify as a head of household.
If at the end of the year you are living apart from your spouse, or you are separated under a provisional decree that has not yet been finalized, you are not consicered divorced. If you care for a child and meet the other head of household tests, you may file as an unmarried head of household. Otherwise, you must file a joint return or as a married person filing separately.
If at the end of the year you live together in common law marriage that is recognized by the law of the state in which you live or the state where the marriage began, you are treated as married.
If your spouse dies during the year, you are treated as married for that entire year and may file a joint return for you and your deceased spouse, assuming you have not remarried before year's end.