Mass. Gen. Laws ch. 258 § 5
The executive officer of a public employer may arbitrate, compromise or settle any claim for damages under this chapter; provided, that any award, compromise or settlement in excess of two thousand five hundred dollars shall be made only with the prior approval of the public attorney for such public employer; provided further, however, that in any case where the public employer is the commonwealth, any award, compromise or settlement in excess of twenty thousand dollars shall be made only with the prior approval of the secretary of administration and finance. The executive officer shall not arbitrate, compromise or settle any such claim before it has been presented to him in writing or after six months have passed from the date upon which such claim was presented to him.
The acceptance by the claimant of any such award, compromise or settlement shall be in writing and shall, except when procured by fraud, be final and conclusive on the claimant, and shall constitute a complete release of any claim against the public employer or against the public employee whose negligent or wrongful act or omission gave rise to such a claim, and a complete bar to any action by the claimant against such public employer or public employee, by reason of the same subject matter.
Mass. Gen. Laws ch. 258, § 5