You can only file as a Qualifying Widow or Widower for the two years after the year in which your spouse died. If you do not remarry in the third year after your spouses death, you are considered single. You will need to use the Single filing status unless you qualify to file as Head of Household.

Is a widow considered unmarried?

Typically, in order to use the qualified widow(er) status, a spouse must remain unmarried for at least two years following the year of the spouses death, as well as meet other standards. After the third year, the surviving spouse can no longer be a qualified widow(er), but must file as single or head of household.