She was an assistant United States attorney and chief of the Del Rio office in the Western District of Texas from 1990 to 1997.
Moses began her federal judicial career as a United States magistrate judge when she was appointed to a four-year part-term in 1997.
Moses was confirmed by the United States Senate on November 14, 2002, and received her commission the next day.
Moses became chief judge on November 18, 2022, when her predecessor Orlando Luis Garcia turned 70 years old.
[2] On October 30, 2023, Moses ordered Border Patrol agents to stop removing concertina wire installed by the government of Texas with the purpose of deterring migrants.