Massachusetts General Laws Part I. Administration of the Government (Ch. 1-182) Ch. 32, § 90B

Any person retired from the service of the commonwealth, or any of its political subdivisions, under any provision of any general or special law or any person claiming under any such retired employee whether as beneficiary, dependent or otherwise, may waive and renounce for himself, his heirs and legal representatives any portion of the pension or retirement allowance payable to him from the commonwealth, or any of its political subdivisions, for such period as he may specify in such waiver and renunciation. Such person may, in lieu of specifying an exact period of time in such waiver and renunciation, include a provision that such shall remain in effect until further notice.