Md. Code, Local Gov't § 19-206

(a) (1) Except as provided in paragraph (2) of this subsection, this section applies only to the following governmental entities: (i) a county; (ii) a public corporation or other political subdivision of the State; or (iii) an agency or instrumentality of a county, public corporation, or other political subdivision of the State. (2) This section does not apply to the following governmental entities: (i) Baltimore City; (ii) a municipality; or (iii) a housing authority under Division II of the Housing and Community Development Article. (b) (1) This section does not apply to a bond that: (i) matures within 1 year after the date of issue and is issued: 1. in anticipation of taxes; 2. to meet current expenses; or 3. to meet an emergency; (ii) is sold to the United States or a unit or instrumentality of the United States; (iii) is issued under a plan of composition approved in a proceeding under Chapter IX of the United States Bankruptcy Act; or (iv) is issued under any other plan to refund or refinance in exchange, bond for bond, for an outstanding maturing debt, other than: 1. a current or floating debt; or 2. a bond under item (i) of this paragraph. (2) This section does not apply to bond or grant anticipation notes issued under Part III of this subtitle. (3) This section does not apply to a bond issued under an enabling act that: (i) states that this section does not apply; or (ii) provides a different method for establishing the maturity of the bond. (c) (1) A governmental entity shall issue bonds on a serial maturity plan. (2) The governmental entity may: (i) vary the amounts of the series; and (ii) provide for the maturity of a series in consecutive annual installments or at longer intervals. (d) (1) The maturity date of the final series shall be based on the purpose for which the bonds are issued: (i) within the time limit that applies under the schedule in paragraph (2) of this subsection; or (ii) if more than one time limit applies, within the shortest applicable time limit. (2) The schedule of maturity dates is as follows: Limit on Purpose of Issue Maturity of Issue Paving existing highways or streets 10 years Airports and buildings constructed or to be constructed thereon 15 years Highway construction 20 years Electric light and power systems 25 years Gas systems 25 years Grade crossing eliminations 25 years Harbor improvements 25 years School construction 25 years All other permanent structures of durable materials 25 years Bridges 30 years Land acquired for permanent improvements 40 years Sewerage installation 40 years Water systems 40 years