Cal. Gov. Code § 53587

In determining the amount of refunding bonds to be issued, the local agency may include all costs of issuing the refunding bonds and of refunding the bonds to be refunded, including the amount of any premium required to be paid to redeem any of the bonds to be refunded, any capitalized interest or bond reserve funds which the local agency determines to be reasonably required, and the cost of any insurance or other credit enhancement authorized by Section 53585.