His parents had a "[v]ery mentally abusive" relationship; Michael was not close to his father, but was encouraged by his mother to pursue his interest in music.

In the mid-1980s, he joined the BMI Lehman Engel Musical Theater Workshop, where he was strongly influenced by a series of mentors and where he segued from writing "camp" songs to more serious work.

[6] In 1995, LaChiusa wrote additional book material for the Broadway musical Chronicle of a Death Foretold (an adaptation of Gabriel García Márquez's 1981 novella of the same name.)

[2] The Wild Party was based on the 1928 poem of the same name by Joseph Moncure March and starred Toni Collette, Mandy Patinkin, and Eartha Kitt.

The Wild Party struggled commercially; after it received seven Tony nominations but failed to win a single award, the producers closed the show.

In 2003, Little Fish, an uncharacteristically cheerful one-act musical for LaChiusa, based on two short stories by Deborah Eisenberg, premiered Off-Broadway.

[1] In October 2005, LaChiusa's musical See What I Wanna See, based on the stories "In a Grove," "The Dragon," and "Kesa and Morito" by Ryūnosuke Akutagawa, opened Off-Broadway at the Public Theater and closed on December 4, 2005.

[10] Queen of the Mist is a musical adaption of the story of Annie Edson Taylor, the first person to survive going over Niagara Falls in a barrel.

Commissioned by Off-Broadway theatre company the Transport Group Queen of the Mist received a developmental lab in fall 2010, and opened in November 2011 at The Gym at Judson.

Originally titled "Tres Ninas" the 2022 production of the musical featured book and lyrics by Ellen Fitzhugh, and direction by Noah Himmelstein.

"[19] LaChiusa is an adjunct professor at the Graduate Musical Theatre Writing Program at the Tisch School of the Arts at New York University.