Mass. Gen. Laws ch. 23G § 33
The lands and tangible personal property of the Agency shall be deemed to be public property used for essential public and governmental purposes and shall be exempt from taxation and from betterments and special assessments.
Nothing in this chapter shall be construed to prevent the taxation to the same extent and in the same manner as other lands are taxed, of lands acquired by the Agency and sold by it, or of lands so acquired by the Agency and leased by it; provided, however, that lands so acquired by the Agency and sold or leased to an urban redevelopment corporation or other entity operating under chapter 121A, or the economic development and industrial corporation of Boston, or such other corporation as may be established by special law for, or other entity operating undersaid chapter 121A and authorized by special law with respect to the redevelopment of lands formerly used for Westover Air Force Base, the Chelsea Naval Hospital, or the Boston Naval Shipyard, including the South Boston Annex, the Boston Army Base and all other lands owned by the United States of America and used in connection with or for purposes related to the operations of the Boston Naval Shipyard or the Boston Army Base, shall be taxed as provided in such chapter or special law and not otherwise.
Mass. Gen. Laws ch. 23G, § 33