They were originally California's first "fully staffed, state-wide transgender legal organization" and were initially a fiscally sponsored project of the National Center for Lesbian Rights.

TLC uses direct legal services, public policy advocacy, and educational opportunities to advance the rights and safety of diverse transgender communities.

[4] The Transgender Law Center helped to revise San Francisco's "Regulations to Prohibit Gender Identity Discrimination" in December 2003,[5] making them more inclusive of people who do not identify as strictly female or male, and to pass legislation in the City of Oakland banning gender identity discrimination in housing, employment, public accommodation, and city services.

[6] In 2015, the TLC joined a lawsuit filed against the California Department of Corrections and Rehabilitation that resulted in a settlement that established a precedent of the state providing gender-affirming medical care.

[8] In 2017 the Seventh Circuit Court of Appeals unanimously ruled in favor of the student, finding that the school's policy violated Title IX and the Equal Protection Clause of the 14th Amendment.