Mass. Gen. Laws ch. 231 § 60D
Notwithstanding the provisions of section seven of chapter two hundred and sixty, any claim by a minor against a health care provider stemming from professional services or health care rendered, whether in contract or tort, based on an alleged act, omission or neglect shall be commenced within three years from the date the cause of action accrues, except that a minor under the full age of six years shall have until his ninth birthday in which the action may be commenced, but in no event shall any such action be commenced more than seven years after occurrence of the act or omission which is the alleged cause of the injury upon which such action is based except where the action is based upon the leaving of a foreign object in the body.
Mass. Gen. Laws ch. 231, § 60D