As a rabbinical student at Hebrew Union College-Jewish Institute of Religion in New York in the 1980s, Denise L. Eger lived away from other seminarians. She quietly started a group for fellow gay and lesbian students, but held the meetings in another borough. By the time of her ordination, she was not formally out of the closet, but her sexuality was known, and no one would hire her. Later, she took the only job offered, with a synagogue formed expressly as a religious refuge for gays.

Since then, the Reform Jewish movement — Rabbi Eger’s spiritual home since childhood — has traveled a long road toward recognizing and embracing same-sex relationships. That journey has led this week to Philadelphia, where she will be installed on Monday as the first openly gay president of the Central Conference of American Rabbis, the rabbinical arm of Reform Judaism.

“It really shows an arc of L.G.B.T. civil rights,” Rabbi Eger said in an interview. “I smile a lot — with a smile of incredulousness.”

Rabbi Eger, the founding rabbi of Congregation Kol Ami in Los Angeles, is not the first openly gay or lesbian clergy member to lead an American rabbinical group. In 2007, the Reconstructionist Rabbinical Association chose Rabbi Toba Spitzer, a lesbian, as its national president. But Reform Jews, with 2,000 rabbis and 862 American congregations, are the largest movement in American Judaism and have a broader role in the Jewish world.