If your spouse passed away in 2025, you are considered to be married the whole year and you can file as
Married Filing Jointly.
If you remarried on or before December 31, 2025, you can file
Married Filing Jointly with your new spouse. You would also need to file a
Married Filing Separately return for your deceased spouse.
If you don't remarry and you have a dependent child, you can use the
Qualifying Surviving Spouse filing status
for two years after the year your spouse died. So, you can use
Married Filing Jointly for your 2025 tax return, then
Qualifying Surviving Spouse filing status for 2026 and 2027.
If your spouse passed away in 2026, you can use the
Married Filing Jointly status on your 2025 and 2026 tax returns.
If you don't qualify to use the
Qualifying Surviving Spouse filing status anymore and you haven't remarried, you should use the
Single or
Head of Household filing status.