Mass. Gen. Laws ch. 112 § 92
Any person licensed by a chiropractic board of any other state having at the time when said person obtained his license a standard equal to that of this commonwealth and which extends similar privileges to persons licensed by the commonwealth, or any person certified by the National Board of Chiropractic Examiners of the United States, may be registered at the discretion of the board upon the payment of a fee as determined annually by the commissioner of administration under the provision of section three B of chapter seven and the production to the board of his diploma, the license obtained in such other state by examination or the proof of his certification by said National Board of Chiropractic Examiners of the United States, and evidence satisfactory to the board that he is of good moral character. The board may accept any or all facts of the examination of said National Board of Chiropractic Examiners of the United States in lieu of equivalent subjects in the examination required under section ninety-four. Any person making application under this section under a license granted by another state shall produce evidence that he has practiced chiropractic under such license for at least three years.
Mass. Gen. Laws ch. 112, § 92