Massachusetts General Laws Part III. Courts, Judicial Officers and Proceedings in Civil Cases (Ch. 211-262) Ch. 223A, § 11

A court of this commonwealth may order a person who is domiciled or is found within this commonwealth to give his testimony or statement or to produce documents or other things for use in a proceeding in a tribunal outside this commonwealth. The order may be made upon the application of any interested person or in response to a letter rogatory and may prescribe the practice and procedure, which may be wholly or in part the practice and procedure of the tribunal outside this commonwealth, for taking the testimony or statement or producing the documents or other things. To the extent that the order does not prescribe otherwise, the practice and procedure shall be in accordance with that of the court of this commonwealth issuing the order. The order may direct that the testimony or statement be given, or document or other thing produced, before a person appointed by the court. The person appointed shall have power to administer any necessary oath.

Notwithstanding any other provision of this section to the contrary and except as required by federal law, a court of this commonwealth shall not order a person who is domiciled or found within this commonwealth to give testimony or statement or produce documents or other things for use in connection with any proceeding in a tribunal outside the commonwealth concerning legally-protected health care activity, as defined in section 11I 1/212 of chapter 12.