From 2009 to 2014, Chung served as a trial attorney in the United States Department of Justice Civil Rights Division.

[9][10][11] In 2011, Chung was involved in prosecuting Frankie Maybee and Sean Popejoy, the first defendants to be sentenced under the Shepherd-Byrd Hate Crimes Prevention Act.

[12][13] On October 27, 2021, President Joe Biden nominated Chung to be the United States attorney for the Western District of Pennsylvania.

President Biden nominated Chung to the seat vacated by Judge D. Brooks Smith, who assumed senior status on December 4, 2021.

[17] Chung was unanimously rated "well qualified" for the circuit judgeship by the American Bar Association's Standing Committee on the Federal Judiciary.

[21] On January 3, 2023, her nomination was returned to the president under Rule XXXI, Paragraph 6 of the United States Senate; she was renominated later the same day.