Mass. R. Dom. Rel. P. 36

(a) Request for admission

A party may serve upon any other party a written request for admission, for purposes of the pending action, only, of the truth of any matters within the scope of Rule 26(b) set forth in the request that relate to statements or opinions of fact or of the application of law to fact, including the genuineness of any documents described in the request. Copies of documents shall be served with the request unless they have been or are otherwise furnished or made available for inspection and copying. The request may, without leave of court, be served upon the plaintiff after commencement of the action and upon any other party with or after service of the summons and complaint upon that party.

Each matter of which an admission is requested shall be separately set forth. The matter is admitted unless, within 30 days after service of the request, or within such shorter or longer time as the court may allow, the party to whom the request is directed serves upon the party requesting the admission either (1) a written statement signed by the party under the penalties of perjury specifically (i) denying the matter or (ii) setting forth in detail why the answering party cannot truthfully admit or deny the matter; or (2) a written objection addressed to the matter, signed by the party or his attorney, but, unless the court shortens the time, a defendant shall not be required to serve answers or objections before the expiration of 45 days after service of the summons and complaint upon him. If objection is made, the reasons therefor shall be stated. A denial shall fairly meet the substance of the requested admission, and when good faith requires that a party qualify his answer or deny only a part of the matter of which an admission is requested, he shall specify so much of it as is true and qualify or deny the remainder. An answering party may not give lack of information or knowledge as a reason for failure to admit or deny unless he states that he has made reasonable inquiry and that the information known or readily obtainable by him is insufficient to enable him to admit or deny. A party who considers that a matter of which an admission has been requested presents a genuine issue for trial may not, on that ground alone, object to the request; he may, subject to the provisions of Rule 37(c), deny the matter or set forth reasons why he cannot admit or deny it. Each admission, denial, objection, or statement shall be preceded by the request to which it responds. The party who has requested the admissions may move to determine the sufficiency of the answers or objections. Unless the court determines that an objection is justified, it shall order that an answer be served. If the court determines that an answer does not comply with the requirements of this rule, it may order either that the matter is admitted or that an amended answer be served. The court may, in lieu of these orders, determine that final disposition of the request be made at a pre-trial conference or at a designated time prior to trial. The provisions of Rule 37(a)(4) apply to the award of expenses incurred in relation to the motion.

(b) Effect of admission

Any matter admitted under this rule is conclusively established unless the court on motion permits withdrawal or amendment of the admission. Subject to the provisions of Rule 16 governing amendment of a pre-trial order, the court may permit withdrawal or amendment when the presentation of the merits of the action will be subserved thereby and the party who obtained the admission fails to satisfy the court that withdrawal or amendment will prejudice him in maintaining his action or defense on the merits. Any admission made by a party under this rule is for the purpose of the pending action only and is not an admission by him for any other purpose nor may it be used against him in any other proceeding.