The Town of Mamaroneck Administrator, Stephen V. Altieri, is responsible for managing the government's every day affairs and informing the town board on the needs and status of various government operations. His office is located on the second floor of the Town Center on Boston Post Road. 

Some of the administrator's duties are acting as the chief spokesperson in collective bargaining with the town unions, submitting a tentative budget to the board every year, attending all board meetings and submitting background information for the board to make policymaking decisions.