Although the income and deductions of both spouses are reported, a joint return may be filed even if only one spouse has income. If one spouse dies during the tax year, the spouses are considered married for the entire year, and thus may file a joint return.
Qualifying Widow(er)
For two years following the death of a spouse, the surviving spouse may file as a “qualifying widow(er)” with a dependent (using the joint filer tax brackets), if he or she satisfies the following requirements:
The surviving spouse was entitled to file a joint return with the deceased spouse in the year of death, even if a joint return was not filed;The surviving spouse has a child or stepchild (excludes a foster child) for whom an exemption can be claimed (although note that the exemption itself was suspended for 2018-2025);
The child lived with the surviving spouse all year; and
The surviving spouse paid more than half of the cost of keeping up the home.2
Finally, if the surviving spouse remarries, he or she can no longer file as a qualifying widow(er), and instead must elect to file as either married filing separately or married filing jointly.
1. Windsor v. U.S., 133 S. Ct. 2675 (2013).