Her best known roles include bail bondswoman Terri Michaels in The Fall Guy on ABC from 1982 to 1985; public defender Christine Sullivan on the NBC sitcom Night Court from 1985 to 1992; Georgie Anne Lahti Hartman on the CBS sitcom Hearts Afire from 1992 to 1995; and Barbara ‘Bunny’ Fletcher, the mother of Detective Erin Lindsay (Sophia Bush), on the NBC drama series Chicago P.D.

Post's early acting credits include a 1979 appearance as a red spandex wearing femme fatale in the science-fiction series Buck Rogers in the 25th Century.

She appeared as Diane Chambers' best friend in the sitcom Cheers, before eventually becoming a regular on the ABC action drama The Fall Guy.

[5] She left The Fall Guy, for her most popular role as Christine Sullivan, the tightly wound public defender on the NBC TV comedy series Night Court; the character was the foil to John Laroquette's misogynistic assistant district attorney, Dan Fielding, and the eventual love interest for Judge Harry Stone (Harry Anderson).

[6] She played Georgie Anne Lahti Hartman on the comedy series Hearts Afire, co-starring John Ritter.

[9] She played a call girl and dominatrix in the 1988 TV movie Tricks of the Trade opposite Cindy Williams, and a singer in Glitz with Jimmy Smits, based on the novel by Elmore Leonard.