Mass. Gen. Laws ch. 209D, § 5-503

Section 5–503. Employer's compliance with 2 or more income withholding orders. If an obligor's employer or other source of periodic income receives 2 or more income withholding orders with respect to the earnings of the same obligor, the employer or other source of periodic income satisfies the terms of the orders if the employer or other source of periodic income complies with the law of the state of the obligor's principal place of employment to establish the priorities for withholding and allocating income withheld for 2 or more child support obligees.