She began taking classes with the Atlantic Theater Company and the Upright Citizens Brigade Theatre, where she met Ilana Glazer.

[13][14][15] From 2009 to 2011, Jacobson and Glazer wrote and performed in a web series titled Broad City, which focused on their lives in New York.

[13] In 2011, cable network FX, working with Amy Poehler as the producer, purchased a script commitment for the series from Glazer and Jacobson.

Glazer and Jacobson then approached Comedy Central, who agreed to purchase the script from FX and order a pilot.

[18][19] Broad City made its broadcast television premiere in January 2014 and was received with positive reviews and strong ratings, becoming Comedy Central's highest-rated first season since 2012 among the younger demographics, including adults 18–34, with an average of 1.2 million viewers.

Club critic Caroline Framke wrote that Broad City was "worth watching" despite its "well-trod premise", and that the series is "remarkably self-possessed, even in its first episode".

[25] Season one of the show received a 96% rating from Rotten Tomatoes, based on reviews from 23 critics, with the site's consensus stating, "From its talented producers to its clever writing and superb leads, Broad City boasts an uncommonly fine pedigree.

[29] Rotten Tomatoes gave the second season a rating of 100%, based on reviews from 11 critics, with the site's consensus: "Led by two of the funniest women on TV, Broad City uses its stars' vibrant chemistry to lend an element of authenticity to the show's chaotic yet enlightening brand of comedy.

[40] In 2022 she served as a writer, producer, co-creator and star of the Amazon series A League of Their Own, based on the 1992 film of the same name, where she plays catcher Carson Shaw.

[46] With drawings throughout, the book of personal essays is centered around Jacobson's solo three week cross-country road trip.

[47] The 320 pages of personal essays and various short stories, although some are comical in nature, largely focus on Jacobson getting over her first love, first relationship with a woman, and general issues of identity.

[48] According to Jacobson, the book is centered around self-reflection: "It's about how I've felt like an internal outsider for my entire life because I just never understood what love was, that I would never get to experience it, and being a public figure only heightened that anxiety.

"[49] In October 2023, Jacobson signed the Artists4Ceasefire open letter to Joe Biden, President of the United States, calling for a ceasefire of the Israeli bombardment of Gaza.