Mass. Gen. Laws ch. 18 § 21
The department shall be subrogated to the rights to support and maintenance of any welfare recipient to the extent of any payments made by the department to such recipient. The department shall obtain from said recipients such information, in the recipient's knowledge and possession, as may be reasonable necessary to enforce the department's right.
When the department proposes to terminate public assistance due to the collection of monthly support in excess of monthly benefits paid, it shall forthwith notify the IV-D agency as set forth in chapter one hundred and nineteen A. When the department terminates public assistance for any reason other than the collection of monthly support in excess of benefits paid, it shall forthwith notify said IV-D agency of such action.
Whenever the department notifies a recipient that it proposes to terminate a recipient from assistance, it shall include in such notice a statement of such recipient's right to continued child support services from the IV-D agency.
Mass. Gen. Laws ch. 18, § 21