Montgomery joined the faculty of the University of Southern California (USC) in 1970 and was promoted to the rank of Professor in 1982.
Montgomery wrote about a hundred research articles and several books, of which Hopf algebras and their actions on rings is her most cited work.
In 1995 she gave an Invited Address at the Joint AMS-Israel Math Union Meeting in Jerusalem.
Her CBMS monograph Hopf Algebras and their Actions on Rings[6] is highly cited.
[12] She was also a member of the National Research Council's Board on Mathematical Sciences and Their Applications (BMSA), serving one year on the Executive Committee.