Mass. Gen. Laws ch. 223, § 6: Counties; actions by or against

Section 6. A local or transitory action by a county shall be brought in the county where the defendant lives or in a county adjoining the plaintiff county. If the defendant lives in the plaintiff county, it shall be brought in an adjoining county. Such action against a county shall, at the election of the plaintiff, be brought in the county where he lives, in the defendant county or in an adjoining county.