Massachusetts Public Library Trustees Handbook 

Most public libraries have a governing board of trustees whose selection is determined by state law, municipal articles of incorporation or regulations. Corporation and association libraries are the exceptions.

There are three types of governance existing in Massachusetts public libraries:

Association/Corporation Libraries: These libraries are established as nonprofit corporations, often in connection with a will, deed or bequest, to provide free library services to the public. Governance is set out in the original instrument of articles of incorporation. These libraries may receive state, local and private funding. In many cases some funding is also derived from the original endowment.

City Libraries: These libraries may be formed by a city on its own initiative. Libraries are governed as specified in the charter of the municipality or by special acts of the state legislature. Funding is provided (primarily) through state and local appropriations.

Town Libraries: These libraries may be established by resolution of the town governing body. They are governed by an elected board of trustees whose number is divisible by three. Special acts such as charter changes may allow for the appointment of trustees. Funding is derived primarily through local and state appropriations.