12 Pa. Code § 133.50
Subject to receipt of funds from the Department the agency shall reimburse the delegate for authorized expenditures. An advance of money, mutually agreed upon, shall be paid to the delegate for authorized expenditures. An advance of money, mutually agreed upon, shall be paid to the delegate for estimated expenditures for mutually agreed upon numbers of months. The delegate shall submit to the agency or the Department vouchers that are sufficient to support payment under accounting procedures established or approved by the accountant of the agency or the accounting requirements of the Department. Within 30 days the agency shall approve or disapprove payment of the vouchers, and shall make additional payments equal to the amount of such approved expenditures to the delegate. The delegate shall not be reimbursed for any cost categories in excess of the approved budget, except as it has received prior written authorization from the agency or the Department, which authorization shall be incorporated into and shall be attached to the contract.
12 Pa. Code § 133.50