Mass. Gen. Laws ch. 122 § 14
Subject to such rules and regulations as the department may prescribe, any person who is a resident of the commonwealth and is affected with any disease, mental illness, mental retardation or suffers any other mental disability, or smallpox, or other diseases dangerous to the public health, or whose health would be injured or endangered by removal, may be admitted to the Tewksbury Hospital, with the approval of the superintendent and the trustees, providing the hospital is suitable for the care and treatment of such person. The department may make rules and regulations for such admission and to facilitate the operation of this section.
The expenses of the maintenance of such a patient shall be paid by him, his executor or administrator, except that persons in need of public assistance shall have the responsibility for payment of such charges fixed in accordance with the provisions of the particular category of assistance under which they are aided. Persons or kindred bound by law to support such needy persons, not eligible for public assistance, shall be assessed in accordance with rates established by the executive office of health and human services or a governmental unit designated by the executive office.
Mass. Gen. Laws ch. 122, § 14