Mary Horstmann is the Deputy Managing Director of Health and Human Services for the City of Philadelphia. She is responsible for overseeing the Department of Behavioral Health and Intellectual DisAbility Services (DBHIDS), the Philadelphia Department of Public Health (PDPH), the Office of Homeless Services (OHS), the Office of Community Empowerment and Opportunity (CEO), the Office of Domestic Violence Strategies (ODVS), and the Mayor’s Commission on Aging (MCOA).

Horstmann is a dedicated public servant who has worked in City government for nearly fifteen years, focused on developing innovative approaches to addressing long-standing challenges. Most recently, before leading HHS, she served as the Senior Director of Policy and Strategic Initiatives for the Managing Director’s Office, supporting efforts to advance policy and legislative priorities of the Kenney Administration, including reducing gun violence, expanding overdose response efforts, and ensuring responsive and high-quality public services.

Horstmann has also worked in community organizing, philanthropy, and grassroots leadership development. She is a resident of South Philadelphia.