Mnuchin joined investment bank Goldman Sachs upon graduating from Yale University in 1985. He worked there for 17 years and eventually became its Chief Information Officer. After he left Goldman Sachs in 2002, he worked for and founded several hedge funds. During the Financial Crisis of 2008, Mnuchin bought failed residential lender IndyMac from the federal government. He renamed it OneWest Bank and rebuilt the bank. In 2015, Mnuchin sold OneWest to CIT Group for $3.4 billion. After the acquisition by CIT, Mnuchin remained at OneWest, and became member of CIT Group's board of directors. Mnuchin was national finance chair for the 2016 Donald Trump presidential campaign. On February 13, 2017, Mnuchin was confirmed by a 53–47 vote in the U.S. Senate.
Following Trump's January 2017 announcement about an investigation into voter registration, it was discovered that Mnuchin is registered to vote in two states. Mnuchin holds registration in both California and New York.
- Trump Taps Hollywood’s Mnuchin for Treasury and Dines With Romney (November 29, 2016). Retrieved on February 18, 2017.
- Abelson, Max (August 31, 2016). Trump’s Top Fundraiser Eyes the Deal of a Lifetime.
- Turner, Matt (November 30, 2016). There’s a long list of reasons people might not like Trump’s pick for Treasury secretary. Retrieved on February 18, 2017.
- Jen Wieczner. "Trump Treasury Pick Mnuchin Is Much Richer Than Most People Thought", Fortune Magazine, January 12, 2017.
- Gabrielle Levy (January 19, 2017). Tiffany Trump, Steve Bannon, Steven Mnuchin Registered to Vote in Multiple States. US News and World Report.