Her other film roles include ...And Justice for All (1979), Housekeeping (1987), Running on Empty (1988), Leaving Normal (1992), and A Beautiful Day in the Neighborhood (2019).

(1981), starring Richard Dreyfuss and John Cassavetes, she was cast as a physician who grows attached to a paralyzed patient seeking the right to leave the hospital.

Lahti was in the bathroom when she won the third award and finally came to the stage following an attempt by show producer John Tinker to accept on her behalf and an interruptive riff by Robin Williams.

[citation needed] Also, Lahti mentioned that she would have liked to have had more time to shoot different perspectives in order to facilitate story arc.

Lahti starred in the executive ADA role on Law & Order: Special Victims Unit as Sonya Paxton while the character Alexandra Cabot (Stephanie March) was in appeals.

She returned to Broadway upon joining the cast of the Tony Award–winning play God of Carnage on November 17, 2009, replacing Marcia Gay Harden.

In September 2011, Lahti starred with Morgan Freeman in the Broadway debut of Dustin Lance Black's play, 8—a reenactment of the federal trial that overturned California's Prop 8 ban on same-sex marriage—as Kris Perry.

[15][16] Her book of autobiographical essays, titled True Stories From an Unreliable Eyewitness, was published in 2018 by Harper Wave.

[17][18] In 2020, Lahti appeared as a guest on the Studio 60 on the Sunset Strip marathon fundraiser episode of The George Lucas Talk Show.