In 1990, Rev. Zillhart founded Lutheran Lesbian and Gay Ministry along with her colleagues, Pastors Jeff Johnson and Ruth Frost, to provide an outreach to the lesbian, gay, bisexual and transgendered community of the San Francisco Bay Area. These three persons were the first openly lesbian and gay people to be ordained in the Lutheran Church.

Phyllis was ordained extra ordinem on January 20, 1990 in a service at historic St. Paulus Lutheran Church in San Francisco that was attended by over 1000 persons, with participation by over 70 clergy members. She was considered ineligible for placement in an ELCA congregation because of a denominational policy that required a pledge of celibacy from gay and lesbian pastors. Phyllis served as the Associate Pastor for Outreach and Evangelism at St. Francis Lutheran Church, San Francisco. She served in this position from 1990 to 2005.

Phyllis currently lives with her partner in the Twin Cities Area of Minnesota. She currently serves as a Chaplain with Fairview Hospice in the Twin Cities Metro. Phyllis was received on the ELCA Clergy Roster in a special “Rite of Reception” in the Saint Paul Area Synod on September 18, 2010, in a special celebration with ELM roster colleagues Ruth Frost and Anita Hill.

She was issued a Letter of Call to Specialized Ministry on Oct. 21, 2010 through the Minneapolis Area Synod of the ELCA.