[Code of Federal Regulations] [Title 48, Volume 1] [Revised as of October 1, 2005] From the U.S. Government Printing Office via GPO Access [CITE: 48CFR43.105] [Page 818] TITLE 48--FEDERAL ACQUISITION REGULATIONS SYSTEM CHAPTER 1--FEDERAL ACQUISITION REGULATION PART 43_CONTRACT MODIFICATIONS--Table of Contents Subpart 43.1_General Sec. 43.105 Availability of funds. (a) The contracting officer shall not execute a contract modification that causes or will cause an increase in funds without having first obtained a certification of fund availability, except for modifications to contracts that-- (1) Are conditioned on availability of funds (see 32.703-2); or (2) Contain a limitation of cost or funds clause (see 32.704). (b) The certification required by paragraph (a) above shall be based on the negotiated price, except that modifications executed before agreement on price may be based on the best available estimate of cost.