Change orders or addenda to public construction contracts of One Million Dollars ($1,000,000.00) or less shall not exceed a 15% cumulative increase in the original amount. Change orders or addenda to public construction contracts of over one million (1,000,000) shall not exceed the greater of One Hundred Fifty Thousand Dollars ($150,000.00) or a ten percent (10%) increase in the original contract.
61 O.S. § 121

Change orders or cumulative change orders that exceed the limits shall require the readvertising of bids on the incomplete portion of the contract.

All change orders shall be formally approved by the board of county commissioners, and the reasons for approval recorded in the permanent records. Alternates or add items bid with the original bid and contained in the awarded contract as options of the awarding agency shall not be construed as change orders.

Note: A highly recommended best practice is that any addendum or change order should be reviewed by the district attorney to ensure compliance.