Mass. Gen. Laws ch. 25A, § 19
(b)
(i) a qualifying zero-emission vehicle that is a medium duty or heavy duty truck, bus or van; or (ii) a qualifying zero-emission vehicle under said subsection (b) if an individual is purchasing or leasing the vehicle and trading in a vehicle with market value that has an internal combustion engine that is not an electric vehicle as defined in section 16; provided, however, that the vehicle with an internal combustion engine has been continuously registered for the previous 2 years: