This is an appeal from a final order of the Department of Health and Rehabilitative Services (HRS) denying El Ponce de Leon Convalescent Center’s (El Ponce) request for an interim rate increase. We affirm on the authority of Greynolds Park Manor, Inc. v. State, 496 So.2d 164 (Fla. 1st DCA 1986) (HRS’s interpretation of Florida Administrative Code Rule 10C-7.-48(6)(i) prohibiting retroactive payments for a closed cost reporting period upheld).

El Ponce’s alternative argument is that HRS is estopped from denying the rate increase due to alleged representations made by certain key HRS employees. The hearing examiner found that no state employee represented to El Ponce that adjustments for alleged underpayments could be reimbursed following the close of the cost reporting period. El Ponce’s claim that such a statement was made involves a credibility determination which was resolved adversely to El Ponce by the hearing examiner. We will not disturb the hearing examiner’s assessment of witness credibility where it is supported by the record.

The other points raised by El Ponce are without merit.

The final order of HRS is, accordingly,

AFFIRMED.