Mass. Gen. Laws ch. 112 § 74D
Any contract or agreement which creates or establishes the terms of a partnership, employment, or any other form of professional relationship with a nurse registered to practice as a registered nurse pursuant to section seventy-four, or a practical nurse registered to practice as a licensed practical nurse pursuant to section seventy-four A, which includes any restriction of the right of such nurse to practice as a nurse in any geographical area for any period of time after the termination of such partnership, employment or professional relationship shall be void and unenforceable with respect to said restriction. Nothing in this section shall render void or unenforceable any other provision of any such contract or agreement.
Mass. Gen. Laws ch. 112, § 74D