For tax purposes, marital status is decided by your legal position on December 31st. Couples who have divorced or legally separated are considered “unmarried individuals” for the entire year, regardless of when the decree went into effect, as long as neither has remarried before the last day of December. Divorced or separated individuals who file a tax return for the year in which they were divorced should use the Single status. If you care for a qualifying dependent child or parent, you may be eligible to use the Head of Household status.
If you live in a different residence than your spouse on December 31st, or are separated under an un-finalized decree, you are still labeled as “married” as far as the IRS is concerned. If you are eligible to file as Head of Household due to the care of a qualifying child, you can file as unmarried. If not, then you are required to file jointly with your spouse, or use the married filing separately status. You have to remember that even when filing separately, you must use the same method of deduction as your spouse: either itemized or standard.
Couples who are engaged in a common law marriage that is legal in their state of residence are considered married for tax purposes. If your spouse passes away, you are still married for the entire tax year, regardless of when the death occurred during the year. You are able to file a joint return for that first year, for you and your deceased spouse, as long as you haven’t remarried by December 31st.