He then served as Director of the Union of American Hebrew Congregations (UAHC) Department of Synagogue and School Extension from 1903 to 1906, superintendent of the Jewish Social Agencies of Chicago, Illinois, from 1908 to 1909, and rabbi of Congregation Beth El in Fort Worth, Texas, from 1909 to 1910.
While serving as a rabbi in Fort Worth, he was the city's commissioner of charities from 1909 to 1910.
[3] In 1910, Zepin returned to the UAHC to again direct the Department of Synagogue and School Extension.
[4] Zepin was a member of the Central Conference of American Rabbis, the Alumni Association of Hebrew Union College, and B'nai B'rith.
[5] His funeral at the Weil Funeral Home was officiated by Rabbis Samuel Wohl, Murray Blackman, Sheldon Blank of HUC-JIR, and Daniel Davis of UAHC in New York.