From 1986 to 1991, she was an assistant United States attorney in the Southern District of New York, where she handled criminal cases, including the prosecution of Ferdinand Marcos, former President of the Philippines.

[2] After working as a legal consultant to the United Nations High Commissioner for Refugees, Livingston was an associate at Paul, Weiss, Rifkind, Wharton & Garrison, a New York City law firm.

[5] In December 2019, Livingston partially dissented from a federal appeals court ruling ordering that Donald Trump comply with a subpoena and turn over his tax returns to the U.S. House of Representatives.

She stated, "I cannot accept the majority's conclusions that 'this case does not concern separation of powers,' and that there is 'minimal at best' risk of distraction to this and future Presidents from legislative subpoenas of this sort."

Livingston said she would send the case back to a lower court and require the House committees to provide more details about the legislative purposes behind their requests before deciding whether the banks must comply.