Mass. Gen. Laws ch. 221B § 4
There are hereby established within the superior court department, the probate and family court department, district court department, and Boston municipal court department of the trial court procedures to expedite the hearing of all child support cases which shall include those portions of motions for temporary orders, motions or complaints for temporary modifications, agreements for modification, complaints under chapter two hundred and seven, two hundred and eight, two hundred and nine, or two hundred and nine C, petitions pursuant to chapter two hundred and nine D or other proceedings involving child support, or involving spousal support when there are children eligible for child support. Child support cases shall also include those portions of motions or complaints seeking to enforce a child or spousal support order described in the previous sentence including complaints for contempt, motions for suspension of income assignment, actions to enforce income assignments of other states, and such other cases as are given to the jurisdiction of child support hearing officers by other provisions of law. Child support cases shall not include instances when the superior court or the probate and family court is to enter a judgment or decree under chapter two hundred and seven or two hundred and eight. The power of the child support hearing officers shall be limited to child support cases, as defined above, and any other issue raised in a motion or complaint shall be heard by a justice of the appropriate court in a separate proceeding.
Mass. Gen. Laws ch. 221B, § 4