Va. Code Ann. § 2.2-4309

A. A public contract may include provisions for modification of the contract during performance, but no fixed-price contract may be increased by more than twenty-five percent of the amount of the contract or $50,000, whichever is greater, without the advance written approval of the Governor or his designee, in the case of state agencies, or the governing body, in the case of political subdivisions. In no event may the amount of any contract, without adequate consideration, be increased for any purpose, including, but not limited to, relief of an offeror from the consequences of an error in its bid or offer.

B. Any public body may extend the term of an existing contract for services to allow completion of any work undertaken but not completed during the original term of the contract.

C. Nothing in this section shall prevent any public body from placing greater restrictions on contract modifications.

D. The provisions of this section shall not limit the amount a party to a public contract may claim or recover against a public body pursuant to § 2.2-4363 or any other applicable statute or regulation. Modifications made by a political subdivision that fail to comply with this section are voidable at the discretion of the governing body, and the unauthorized approval of a modification cannot be the basis of a contractual claim as set forth in § 2.2-4363 .

1982, c. 647, §§ 11-45, 11-55; 1984, c. 764; 1985, c. 286; 1987, cc. 194, 248; 1989, c. 235; 1990, c. 395; 1991, c. 175; 1993, cc. 110, 505, 638, 971; 1996, cc. 145 , 897 , 902 , 950 , 1038 ; 1998, cc. 222 , 619 , 666 , 697 , 791 ; 1999, cc. 160 , 194 , 1021 , 1024 ; 2000, cc. 242 , 637 , 664 , 696 , 927 ; 2001, c. 844 ; 2015, c. 569 .