The Borough of New Cumberland exists under the Pennsylvania Borough Code which is a statute adopted by the Pennsylvania General Assembly as the basic law governing boroughs. The borough is operated by a Council, Mayor, and appointed officials.

Borough Council is the governing body. Seven members of Council are elected at large for 4-year terms. Council holds regular monthly meetings. Council is responsible for levying taxes, enacting ordinances and resolutions, establishing policies, providing services, and promoting the health, safety, and welfare of the borough residents.

The Mayor is also an elected position with a term of 4 years. Although not a member of the Borough Council, the Mayor may attend all Council meetings and take part in the discussions. The Mayor may cast the deciding vote when a tie occurs and may approve or veto every ordinance or resolution of legislative nature passed by Council. If the Mayor vetoes an ordinance or resolution, Council may override it with a two-thirds vote. The Mayor has the responsibility for the administration of the police department.

The Borough of New Cumberland operates under the Council-Manager form of government. This system combines the political leadership and representation of elected officials with the administrative and professional experience of an appointed manager. It is the manager's responsibility to implement and over-see the policies and programs set forth by Council on a day-to-day basis.

Council also appoints professionals such as a Solicitor, an Auditor, an Engineer, and an Insurance Broker to act in consulting and advisory capacities. The Tax Collector, Tax Assessor, and Constables are positions elected at large by the public.