She has written many television scripts including The Larry Sanders Show, Saturday Night Live and Seinfeld.

[7] While studying for a theater degree at Harpur College (now Binghamton University), Leifer accompanied her then boyfriend Paul Reiser to a comedy club to see him perform at the open mic night at Catch A Rising Star.

[8][4] In 1977, she began performing stand-up comedy and transferred to Queens College to be closer to the club scene.

Early in her career, a critic from Variety wrote a review on one of Leifer's sets, saying, "She still has much to absorb in operating in the comedic area, but, with further experience, has a good chance at the brass ring.

[10] She has gotten tremendously positive feedback over the years, known for her infectious laugh, witty observational comedy, and clean-cut humor.

Leifer was hired by Al Franken and Jim Downey to work as a writer for the popular sketch comedy show.

[14] Leifer recalls her time at SNL being a great opportunity to grow and learn as a writer, but the division caused by Michaels' indifference impacted her time working there, as she recalls "it felt like being asked to play on a Beatles album by Ringo.

Leifer starred in, created, and executive-produced the 1997 WB sitcom Alright Already, which only ran one season.

[18] Leifer has also written for several television shows, such as Devious Maids, Modern Family, and Rules of Engagement.

[20] The episodes Leifer wrote, listed chronologically, are:[21] Her work on Seinfeld garnered her a Primetime Emmy Award nomination.

"[24] One of the most important things she learned as a writer from working on Seinfeld was to "mine your own life for comedy ideas.

[29] She was also part of Superman's 50th Anniversary: A Celebration of the Man of Steel as Beth Lewis, Lois Lane's best friend.

Her first book of humorous essays, entitled When You Lie About Your Age, The Terrorists Win, was released on March 10, 2009.

At age 40, Leifer met her current wife, Lori Wolf, and realized she was gay, not "just looking for a fling" as she originally intended.

After receiving a homophobic letter, Leifer recalls feeling "I thought I was prepared for something like that, but even 13 years in, it's still a kick in the face.

[36] In 2007 they purchased a $3.2-million, 5,000-square-foot (460 m2) home in the Santa Monica Hills,[37] as part of their preparations to adopt their nine-month-old son, Bruno Leifer-Wolf, who was born in Guatemala in 2006.

"[38][39] Leifer has been advocate for animal rights and made testimonials for PETA about her decision to become vegan, encouraging others to do the same.