Which modification type requires signatures from both the contractor and the contracting officer?

A bilateral modification is a change to a contract that requires the agreement and signature of both parties involved, which typically includes the contractor and the contracting officer. This type of modification is often used when both parties need to agree on changes to the scope of work, performance terms, or contract price, ensuring that both parties share mutual consent over the alterations being made.

This requirement for signatures highlights the collaborative nature of bilateral modifications, as both the contractor and contracting officer must formally agree to the terms. This ensures that there is clarity and mutual understanding regarding the modifications being made to the contract, preventing any potential disputes arising from unilateral changes.

In contrast, unilateral modifications can be executed by one party—usually the contracting officer—without requiring approval from the contractor, making them inherently different from bilateral modifications. Other types such as temporary or supplemental modifications may have specific uses but do not mandate signatures from both parties for validity, unlike bilateral modifications.