In 2020, she announced her candidacy for Mayor of Baltimore but lost to Council President Brandon Scott in the June 2020 Democratic primary.

Miller spent 26 years working for T. Rowe Price Group, Inc., where she was the director of the Fixed Income Division and a member of the firm's Management Committee.

Miller joined Treasury as President Obama's appointee as Assistant Secretary of the Treasury for Financial Markets, where she advised the Secretary on broad matters of domestic finance, financial markets, federal, state and local finance, and federal government lending policies.

[3] Miller served as President Obama's Under Secretary for Domestic Finance in the Department of the Treasury from March 2012 to September 2014.

[5] Miller received the Alexander Hamilton Award for Distinguished Service from the Columbia College Alumni Association[6] upon her retirement from Treasury.