Maryland State Finance and Procurement Section 6-202
§ 6-202.
  Collateral that may be used under this subtitle shall be:
    (1)   an obligation of the United States or any of its agencies;
    (2)   an obligation guaranteed by the United States or by any of its agencies;
    (3)   an obligation insured by the United States;
    (4)   an obligation of the State or any of its units or instrumentalities;
    (5)   an obligation of a county of the State or any of its agencies;
    (6)   an obligation of a municipal corporation in the State or any of its agencies;
    (7)   an obligation of any other governmental authority in the State;
    (8)   an obligation of the Inter-America Development Bank;
    (9)   an obligation of the World Bank;
    (10)   an obligation of the following government-sponsored enterprises:
      (i)   the Federal Home Loan Bank System;
      (ii)   the Federal Home Loan Mortgage Corporation;
      (iii)   the Federal National Mortgage Association;
      (iv)   the Farm Credit System;
      (v)   the Federal Agricultural Mortgage Corporation; and
      (vi)   the Student Loan Marketing Association;
    (11)   a surety bond if:
      (i)   subject to the terms and conditions of the bond, it is irrevocable and absolute;
      (ii)   the surety bond is issued by an insurance company authorized to do business in this State;
      (iii)   the issuer of the surety bonds does not provide surety bonds for any one financial institution in an amount that exceeds 10% of the surety bond insurer's policyholders' surplus and contingency reserve, net of reinsurance; and
      (iv)   the claims-paying ability of the authorized insurance company is rated, at all relevant times, in the highest category by at least two nationally recognized rating agencies acceptable to the Treasurer; or
    (12)   an obligation or security of, or other interest in, any open-end or closed-end management type investment company or investment trust registered under the provisions of the federal Investment Company Act of 1940, 15 U.S.C. § 80a-1 et seq., if:
      (i)   the portfolio of the open-end or closed-end management type investment company or investment trust is limited to direct obligations of the United States government and to repurchase agreements fully collateralized by United States government obligations; and
      (ii)   the open-end or closed-end management type investment company or investment trust takes delivery of that collateral, either directly or through an authorized custodian.