To the best of my knowledge all Orthodox denominations separate genders for prayers (For context,
mechitzah is a divider, Rabbi Soloveitchik is widely regarded as the father of Modern Orthodoxy and Chovevei Torah is considered barely Orthodox if-at-all by other Orthodox groups):
Orthodox Judaism is divided on whether a synagogue mechitza represents binding law or a custom. During the middle portion of the 20th century, there were a substantial number of synagogues which considered themselves Orthodox but did not have one.
[2] The influential
Haredi Posek (decisor)
Moshe Feinstein held that a mechitza is required as a matter of Biblical law, holding that the statement in Zechariah 12:12-14 represents not a prophecy about future circumstances but binding
Sinaitic law,
Halacha LeMoshe MiSinai, regarding present circumstances. He declared that Orthodox Jews are prohibited from praying in a synagogue without one. Rabbi
Joseph Soloveitchik held that a separation of men and women is Biblically required, while the physical mechitza was required by Rabbinic decree. These views have gained adherence over the later portion of the 20th century.
The
Orthodox Union (OU), the main body of Modern Orthodox synagogues in the United States, adopted a policy of not accepting synagogues without mechitzot as new members, and strongly encouraging existing synagogues to adopt them.
[2] In 2002, Rabbi
Avi Weiss of
Yeshivat Chovevei Torah, stated that "As an Orthodox institution, Yeshivat Chovevei Torah requires its students to daven in synagogues with mechitzot." The
Jewish Ledger reported that as of 2005, "
Beth Midrash Hagadol-Beth Joseph remains the only synagogue in the
country affiliated with the Orthodox Union (OU) to have so-called 'mixed seating.'"
[8] However, in 2015 this synagogue decided to leave the OU, after learning that the OU was planning to expel it from OU membership.
[9] Mixed-seating Orthodox synagogues (
Conservadox), which were a prevalent minority as late as a generation ago, have now all but disappeared. The
partnership minyan movement, which seeks a greater synagogue role for women within an Orthodox context, requires a mechitza.
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