N.Y. Comp. Codes R. & Regs. tit. 9, § 1646-5.3 – Contract changes.

(a) A contract change generally involves an adjustment in the contract price, or an extension of time, or both. Changes in contracts are accomplished by the issuance of an order in writing by the authorized person designated by the local agency to administer the contracts. Orders for contract changes shall never be issued verbally. Orders to change contracts are classified as follows:
1. (1) Change orders. Change orders authorize a variation in the contract terms. The change order must state whether there is to be an adjustment of the contract price, and the exact amount of such adjustment, if any.
2. (2) Proceed orders. Proceed orders authorize a variation in the contract terms without stating a definite price, said price being subject to future determination. A proceed order must be superseded by a change order as soon as the definite price is determined.
(b) The prior written approval of the division is required for any change in the contract amount in excess of a “maximum sum”. Such “maximum sum” may be stipulated either in the loan contract or in the individual construction contracts.
(c) All contract changes shall be recorded in the contractors ledger.
(d) Where the contract change involves a change in the contract amount, a journal entry, supported by the letter of the division approving the change or by the approved change order shall be made adjusting the amounts previously recorded in account 1500, Incompleted Contracts, and account 2400, Contract Awards.