In the private sector, she worked as a lawyer at Reed Smith and Squire Patton Boggs. Singh served as the Deputy Assistant Secretary in the Bureau of Economic, Energy and Business Affairs during the Bush administration.[4] In addition, she was an executive director at J.P. Morgan Chase & Co. in the International Government Relations group. Manisha Singh was designated Acting Under Secretary of State for Economic Growth, Energy, and the Environment Shield Ombudsperson by the President in September 2018 until Keith J. Krach was confirmed as Under Secretary of State. She also serves as the Foreign Affairs Sous Sherpa for the 45th G7 summit.
Unanimously confirmed by the Senate and sworn in as assistant secretary of State in November 2017, she leads a team of over 200 employees in the Bureau of Economic and Business Affairs, which also serves as the home bureau for economic officers posted in embassies around the world. She is the first woman appointed to the role and is responsible for advancing American prosperity, entrepreneurship and innovation worldwide.
In September 2018, during a congressional hearing and in her role as assistant secretary of state, Singh reminded Congress, that if Russia did not achieve compliance with international chemical weapons laws by the November deadline, the government would not hesitate to implement the extreme sanctions announced in August.[11]