This chapter helps you determine which filing status to use. There are five filing statuses.

• Single.
• Married Filing Jointly.
• Married Filing Separately.
• Head of Household.
• Qualifying Widow(er) With Dependent Child.

You must determine your filing status before you can determine your filing requirements (chapter 1), standard deduction (chapter 20), and tax (chapter 29). You also use your filing status to determine whether you are eligible to claim certain deductions and credits.

In general, your filing status depends on whether you are considered unmarried or married. For federal tax purposes, a marriage means only a legal union between a man and a woman as husband and wife. The word "spouse" means a person of the opposite sex who is a husband or a wife.

You are considered unmarried for the whole year if, on the last day of your tax year, you are unmarried or legally separated from your spouse under a divorce or separate maintenance decree. State law governs whether you are married or legally separated under a divorce or separate maintenance decree.

If you are divorced under a final decree by the last day of the year, you are considered unmarried for the whole year.

If you obtain a divorce for the sole purpose of filing tax returns as unmarried individuals, and at the time of divorce you intend to and do, in fact remarry each other in the next tax year, you and your spouse must file as married individuals in both years.

If you obtain a court decree of annulment, which holds that no valid marriage ever existed, you are considered unmarried even if you filed joint returns for earlier years. You must file Form 1040X, Amended U.S. Individual Income Tax Return, claiming single or head of household status for all tax years that are affected by the annulment and are not closed by the statute of limitations for filing a tax return. Generally, for a credit or refund, you must file Form 1040X within 3 years (including extensions) after the date you filed your original return or within 2 years after the date you paid the tax, whichever is later. If you filed your original return early (for example, March 1), your return is considered filed on the due date (generally April 15). However, if you had an extension to file (for example, until October 15) but you filed earlier and we received it July 1, your return is considered filed on July 1.

If you are considered unmarried, you may be able to file as a head of household or as a qualifying widow(er) with a dependent child. See Head of Household and Qualifying Widow(er) With Dependent Child to see if you qualify.

If you are considered married, you and your spouse can file a joint return or separate returns.

You are considered married for the whole year if on the last day of your tax year you and your spouse meet any one of the following tests.

1. You are married and living together as husband and wife.
2. You are living together in a common law marriage recognized in the state where you now live or in the state where the common law marriage began.
3. You are married and living apart, but not legally separated under a decree of divorce or separate maintenance.
4. You are separated under an interlocutory (not final) decree of divorce.

If your spouse died during the year, you are considered married for the whole year for filing status purposes.

If you did not remarry before the end of the tax year, you can file a joint return for yourself and your deceased spouse. For the next 2 years, you may be entitled to the special benefits described later under Qualifying Widow(er) With Dependent Child.

If you remarried before the end of the tax year, you can file a joint return with your new spouse. Your deceased spouse's filing status is married filing separately for that year.

If you live apart from your spouse and meet certain tests, you may be able to file as head of household even if you are not divorced or legally separated. If you qualify to file as head of household instead of as married filing separately, your standard deduction will be higher. Also, your tax may be lower, and you may be able to claim the earned income credit. See Head of Household, later.