30 ILCS 330/16
The State of Illinois is authorized to issue, sell, and provide for the retirement of General Obligation Bonds of the State of Illinois in the amount of $4,839,025,000, at any time and from time to time outstanding, for the purpose of refunding any State of Illinois general obligation Bonds then outstanding, including (i) the payment of any redemption premium thereon, (ii) any reasonable expenses of such refunding, (iii) any interest accrued or to accrue to the earliest or any subsequent date of redemption or maturity of such outstanding Bonds, (iv) for fiscal year 2019 only, any necessary payments to providers of interest rate exchange agreements in connection with the termination of such agreements by the State in connection with the refunding, and (v) any interest to accrue to the first interest payment on the refunding Bonds; provided that no refunding Bonds shall be offered for sale unless the net present value of debt service savings to be achieved by the issuance of the refunding Bonds is 3% or more of the principal amount of the refunded Bonds or the principal amount of the refunding Bonds to be issued; refunding Bonds shall mature within the term of the Bonds being refunded in compliance with paragraph (e) of Section 9 of Article IX of the Illinois Constitution of 1970 .
The Governor shall notify the State Treasurer and Comptroller of such refunding. The proceeds received from the sale of refunding Bonds shall be used for the retirement at maturity or redemption of such outstanding Bonds on any maturity or redemption date and, pending such use, shall be placed in escrow, subject to such terms and conditions as shall be provided for in the Bond Sale Order relating to the Refunding Bonds. Proceeds not needed for deposit in an escrow account shall be deposited in the General Obligation Bond Retirement and Interest Fund. This Act shall constitute an irrevocable and continuing appropriation of all amounts necessary to establish an escrow account for the purpose of refunding outstanding general obligation Bonds and to pay the reasonable expenses of such refunding and of the issuance and sale of the refunding Bonds. Any such escrowed proceeds may be invested and reinvested in direct obligations of the United States of America, maturing at such time or times as shall be appropriate to assure the prompt payment, when due, of the principal of and interest and redemption premium, if any, on the refunded Bonds. After the terms of the escrow have been fully satisfied, any remaining balance of such proceeds and interest, income and profits earned or realized on the investments thereof shall be paid into the General Revenue Fund. The liability of the State upon the Bonds shall continue, provided that the holders thereof shall thereafter be entitled to payment only out of the moneys deposited in the escrow account.
Except as otherwise herein provided in this Section, such refunding Bonds shall in all other respects be subject to the terms and conditions of this Act.
30 ILCS 330/16