Municipalities can raise tax revenue beyond annual statutory limits imposed by Proposition 2½ M.G.L Ch. 59 Sec. 21C through a referendum to approve an override or an exclusion, or they can reduce the amount taxed through an underride. With one exception, legal authority to place a question on the ballot rests solely with the board of selectmen, city council or town council.
Towns only can approve a contingent appropriation (Ch. 59 Sec. 21C(m)) which is usually a single additional expenditure, or multiple appropriations made subject to subsequent voter approval of a funding source. Most often, that funding source is additional tax revenue raised through an override, debt exclusion or capital expenditure exclusion. While town meeting must approve the contingent appropriation, only the selectmen can actually place the referendum on the ballot for voter approval. When a contingent appropriation is approved at an annual town meeting, the related referendum must be placed before the voters prior to September 15. When a special town meeting approves contingent spending, the override or exclusion vote must occur within 90 days. In any case, a failed referendum may be returned to the voters on subsequent ballots, but if not approved by the applicable deadline, the appropriation is null and void.
Massachusetts General Law, Chapter 39, section 10: