Massachusetts General Laws Part I. Administration of the Government (Ch. 1-182) Ch. 40M, § 11

(A) A group shall file with the commissioner its rating plan.

(B) Each group shall be audited at least annually by an auditor acceptable to the commissioner to verify proper rating. A report of the audit shall be filed with the commissioner in a form prescribed by the commissioner. A group or any member thereof may request a hearing on any objections to the rating. If the commissioner determines that as a result of an improper rating a member's premium contribution is insufficient, he shall order the group to assess that member an amount equal to the deficiency. If the commissioner determines that as a result of an improper rating a member's premium is excessive, he shall order the group to refund to the member the excess collected. The audit shall be at the expense of the group.