Your filing status determines your income tax rate and standard deduction. If you're a recent widow(er), it's in your best interest to file your taxes under the filing status that saves you the most money.
Filing a Joint Return
You can file a joint return with your deceased spouse for the year of death unless you remarry during that year. It's your responsibility to be sure a return is filed for your spouse.
If you remarry in the year of your spouse's death, you can't file a joint return with the deceased spouse. You can file a joint return with the new spouse or you and your new spouse may each file a separate return. If a return is required for the deceased spouse, use the Married Filing Separately status. If you're a surviving spouse with no gross income, you can be claimed as an exemption on your deceased spouse's separate return and on your new spouse's separate return. If you file a joint return with your new spouse, your exemption can be claimed only on that joint return.
Individuals who meet certain requirements may use this filing status for the 2 tax years following, but not including, the year of death:
You were entitled to file a joint return with your spouse for the year in which he or she died (it doesn't matter whether you actually filed a joint return).
You didn't remarry before the close of the tax year.
You have a child or stepchild (but not a foster child) who qualifies as your dependent.
You furnished more than half the cost of maintaining your home, which was the main home of your dependent child for the entire year (except for temporary absences).
If you file as a qualifying widow(er) you can't claim an exemption for your deceased spouse. You can, however, use the Married Filing Jointly tax table or tax rate schedule. The Qualifying Widow(er) standard deduction is the same as that for a married couple filing jointly.
Filing as Single
Unless you qualify to use the Qualifying Widow(er) status or you get remarried, you'll generally need to file as Single after your spouse dies. The deductions are lower and the tax rates are different for this status.