Mass. Gen. Laws ch. 112 § 242
Upon payment of a fee and the submission of an application provided by the board, the board may issue a license without examination to an applicant who is legally registered as a journeyperson or master sheet metal worker in any other state or country whose requirements for obtaining and maintaining registration, in the opinion of the board, are at least substantially equivalent to the requirements in the commonwealth, provided such other state or country has a reciprocal privilege to licensees registered by the board. The board may require additional education if it determines that the standards required for sheet metal work in another state or country are inconsistent with the standards in effect in the commonwealth.
Mass. Gen. Laws ch. 112, § 242