Armstrong's professional acting career began in 1975 with the
Off-Off Broadway debut,
Harmony House. Then, in 1977, Armstrong made her television debut as Julia Peters on the CBS sitcom,
On Our Own. In 1978 Armstrong starred opposite
Richard Thomas in her first TV-movie,
Getting Married. Also in 1978, she starred in the TV movie "How to Pick Up Girls!" with
Desi Arnaz Jr. She co-starred again with Richard Thomas in a 1981 stage production in
Seattle of
Neil Simon's
Barefoot in the Park, from which a video was made for HBO broadcast that year. Armstrong continued to make several films for both the big and small screens in the 1980s, among them
High Road to China opposite
Tom Selleck;
Jaws 3-D with
Dennis Quaid;
Alan Alda's
The Four Seasons; the TV miniseries
Lace; and
Nothing in Common, starring
Tom Hanks and
Jackie Gleason. The 1990s brought Armstrong to her best-known role, playing Patty Chase on the series
My So-Called Life. She later starred in several television films. In 2000, she appeared on the NBC sitcom
Frasier, in the episode "Mary Christmas." In 2008, Armstrong played Penelope Kendall on ABC's
Boston Legal. Armstrong remains active in films, television, and the stage. She had a recurring role in the Showtime series
House of Lies as Julianne Hotschragar. She also appeared in
Castle,
Mad Men,
NCIS,
S.W.A.T., and ''
Grey's Anatomy''. == Personal life ==