Mass. Gen. Laws ch. 176O, § 15
(d) A carrier shall provide coverage for health services for up to 30 days from the effective date of coverage to a new insured by a provider who is not a participating provider in the carrier's network if:
(e) A carrier may condition coverage of continued treatment by a provider under subsections (a) to (d), inclusive, upon the provider's agreeing:
(g) No carrier shall require an insured to obtain a referral or prior authorization from a primary care provider for specialty care provided by an obstetrician, gynecologist, certified nurse-midwife or family practitioner participating in such carrier's health care provider network for the following: