Minn. Stat. § 446A.18: PURCHASE AND CANCELLATION BY AUTHORITY.

Subject to agreements with bondholders that may then exist, the authority may purchase out of funds available for the purpose, bonds of the authority which shall then be canceled, at a price not exceeding the following amounts:

(1) if the bonds are then redeemable, the redemption price then applicable plus accrued interest to the next interest payment date of the bonds; or

(2) if the bonds are not redeemable, the redemption price applicable on the first date after the purchase upon which the bonds become subject to redemption plus accrued interest to that date.