The spouse may still apply under a widow(er) petition.

The case is automatically denied.

The surviving spouse can usually self-petition with Form I-360 as a widow(er) of a U.S. citizen, as long as the marriage was genuine and they file within 2 years of the citizen’s death.

They might qualify for humanitarian reinstatement.

If the U.S. citizen had already filed Form I-130 before passing, USCIS may automatically convert it to a widow(er) petition, allowing the process to continue.