The primary will be Feb. 4 and the general election will be held on April 28, USA Today reported.
Rockeymoore Cummings told Maddow that she fought along with her husband for the past 12 years.
She said she will continue his vision for the district, The Baltimore Sun reported.
"I've been on this path for fighting for the soul of our democracy, for fighting for health care, education, for a better America for all. He wanted me to continue this fight and I'm going to continue this fight and run the race and prayerfully win," Rockeymore Cummings said, according to USA Today.
According to Rockeymoore Cummings' official biography, she married Rep. Cummings in 2008 after the couple met while working on Capitol Hill in the 1990s.
Rep. Cummings died of cancer on Oct. 17, The Sun reported.