In 1903, Bernstein became managing director of the Hebrew Sheltering Guardian Orphan Asylum in Pleasantville. He held that position for fifteen years, during which time he organized and developed one of the largest cottage home plans in the country for the care and education of dependent children as well as the Home Bureau of the Hebrew Sheltering Guardian Society, the first comprehensive Jewish foster home bureau. He then worked as executive director of the Bureau of Social Research in New York City, conducting surveys on child welfare and juvenile delinquency in the Jewish communities of Chicago and Philadelphia in 1919 and New York City in 1920. In 1921, he moved to Pittsburgh, Pennsylvania, and became director of the local Federation of Jewish Philanthropies. He began lecturing for the University of Pittsburgh Department of Philosophy in 1925, and in 1928 he became special lecturer on child care at the Graduate School of Jewish Social Work in New York City.
