(1) In the case of a catastrophic event or extraordinary circumstance that would directly impact the cost of medical services provided by an RHC or FQHC, or upon mutual agreement of the department and the RHC or FQHC the department may provide for payment in any year to an RHC or FQHC for services described in section 1905(a) (2) (B) and (C) of the Social Security Act in an amount determined under an alternative payment methodology that:

(a) is agreed to by the department and the RHC or FQHC; and

(b) results in payment to the RHC or FQHC of an amount which is at least equal to the amount otherwise required to be paid to the RHC or FQHC under the medicaid prospective payment system.