On May 8, 2014, President Barack Obama nominated Sannes to serve as a United States district judge of the United States District Court for the Northern District of New York, to the seat vacated by Judge Norman A. Mordue, who assumed senior status on June 30, 2013.[3] She received a hearing on her nomination on June 24, 2014.[4] On July 17, 2014, her nomination was reported out of committee by a voice vote.[5] On November 18, 2014, Senate Majority Leader Harry Reid filed for cloture on her nomination. On November 19, 2014, the United States Senate invoked cloture on her nomination by a 55–42 vote.[6] On November 20, 2014, her nomination was confirmed by a 96–0 vote.[7] She received her judicial commission on November 21, 2014.[2] Sannes became chief judge on August 31, 2022.[8]