Section 43.103 - Types of contract modificationsContract modifications are of the following types:
(a)Bilateral. A bilateral modification (supplemental agreement) is a contract modification that is signed by the contractor and the contracting officer. Bilateral modifications are used to-(1) Make negotiated equitable adjustments resulting from the issuance of a change order;(2) Definitize letter contracts; and(3) Reflect other agreements of the parties modifying the terms of contracts.(b)Unilateral. A unilateral modification is a contract modification that is signed only by the contracting officer. Unilateral modifications are used, for example, to- (1) Make administrative changes;(3) Make changes authorized by clauses other than a changes clause (e.g., Property clause, Options clause, or Suspension of Work clause); and(4) Issue termination notices.48 FR 42386, Sept. 19, 1983, as amended at 66 FR 2133 , Jan. 10, 2001