He previously served as the Deputy United States Trade Representative,[1] Gerrish was previously a partner in the International Trade Group at Skadden, Arps, Slate, Meagher & Flom.

Gerrish was a member of President Trump's 2016 trade transition team.

[6][7] Gerrish was chosen to lead the US-delegation in trade-talks with China beginning in mid-January 2019.

He is seen as having a close world view to Robert Lighthizer, who mentored him, and, thus, was expected to take a tough stance against China in these talks.

[8][9] In August 2020, he rejoined Skadden, Arps, Slate, Meagher & Flom.