Ambassador to International Organizations in Vienna from 2012 to 2014,[3] as well as interim coordinator for efforts to implement President Barack Obama's Iran Nuclear Deal in 2015.

[4] Macmanus was President Donald Trump's nominee to become United States Ambassador to Colombia.

[6] In 2019, Philip Goldberg replaced Macmanus as nominee to be the next United States Ambassador to Colombia.

[12][13] On November 29, 2017, President Donald Trump nominated Macmanus to serve as the United States Ambassador to Colombia.

[14][15] In May 2019, it was announced that Philip Goldberg would replace Macmanus as nominee to be the next United States Ambassador to Colombia.