Mass. Gen. Laws ch. 44 § 19
Cities, towns and districts shall not issue any notes payable on demand, but shall provide for the payment of all debts, except temporary loans incurred under sections 4, 6, 6A, 8C, and 17 or under section 3 of chapter 74 of the acts of 1945, by annual payments that will extinguish the same at maturity, and so that the first of these annual payments on account of any serial loan shall be made not later than the end of the next complete fiscal year commencing after the date of the bonds or notes issued for the serial loan, and shall be arranged so that for each issue the amounts payable in the several years for principal and interest combined shall be as nearly equal as practicable in the opinion of the officers authorized to issue the bonds or notes or, in the alternative, in accordance with a schedule providing a more rapid amortization of principal; and these annual amounts, together with the interest on all debts, shall, without further vote, be assessed until the debt is extinguished.
Notwithstanding any general or special law to the contrary, the final payment on account of any bonds issued by a city, town or district may be made not later than the end of the fiscal year in which such bonds would otherwise have been payable under this chapter, or any other statutory authority under which the issuance of any such bonds was otherwise authorized.
Mass. Gen. Laws ch. 44, § 19