In 1914, R. Katz went to the Volozhin Yeshiva for two years where he was ordained a Rabbi by R. Refael Shapiro, the son-in-law of the Neziv. In 1916 he studied under Rabbi Shlomo Poliatchik, the renowned Maitziter Illuy. In 1918 he returned to Telz, where he married the Perel Leah, the daughter of R. Yosef Leib Bloch. In 1922, a postgraduate institute (Kollel) was founded in Telz and R. Katz was appointed Head of the Institute (Rosh Hakollel).

In 1934, R. Katz was one of the founders of the Zeirei Agudath Israel in Lithuania and he served as the head of the Board of Action (Va’ad Hapoel). Together with his brother in law, R. Eliyahu Meir Bloch, he also served as one of the editors of the Agudah newspaper in Lithuania: “Dos Yiddishe Lebben”. He participated in the first Knessiah Gedolah of the Agudath Israel in 1923 and at the third Knessiah Gedolah in 1937 he was appointed a member of the International Action Committee (Va’ad Hapoel Ha’olami).

In 1940, R. Katz and his brother in law R. Eliyahu Meir Bloch managed to travel out of Soviet occupied Lithuania and make their way to the United States, in the hope of re-establishing the Rabbinical College of Telshe and bringing over its faculty and student body. Both R. Katz and R. Bloch were unable to bring their wives and children, the fate of whom remained unknown to them until 1944. In October 1942 R. Katz and his brother in law R. Bloch re-established the Telz Yeshiva in Cleveland, Ohio. Together, in 1943 they established a Jewish day school: The Hebrew Academy of Cleveland.

In 1954 R. Eliyahu Meir Bloch died, and R. Katz became Rosh Yeshiva. In addition he served as a member on the Moetzes Gedolei HaTorah of the Agudath Israel. In 1960 he established Telshe Chicago - a branch of the yeshiva in Chicago, Illinois. On November 17th 1964 R. Katz suffered a massive heart attack and died.