Yeager served on the Santa Clara County Board of Supervisors, on the San José City Council, and on the San José/Evergreen Community College Board. For twelve years, he taught political science at San Jose State University. Yeager became the first openly gay elected official in Santa Clara County in 1992, having come out publicly in 1984. During his term as San José City Council member, he flew the rainbow flag from City Hall in 2001. In his role as County Supervisor, he presided over the first same-sex marriages in 2008 as well as 2013.
In his book “Run”, Yeager relates the story of political activism of the LGBTQ+ community in San José and Silicon Valley as he experienced it in his long years as a politician. He gives advice on how to run for office as a member of the LGBTQ+ community and how to achieve legislative measures while in office.