Question: is tefillin worn on chol hamoed?
Answer: Sephardic Jews, Ashkenazi followers of the Vilna Gaon and Chabad Chassidim do not (as on festivals). Most other Hasidim, or those with Hasidic ancestry, also do not don tefillin during Chol HaMoed. ... However in all Hasidic communities married (or formerly married) men do not wear tefillin during Chol HaMoed.