What is a contract modification?
A contract modification (mod) is a formal change to an existing government contract — adjusting scope, price, delivery, or terms. Mods are common: they extend option years, add or remove work, correct errors, and adjust for changed conditions. Both parties must agree to bilateral mods; unilateral mods (like exercising an option) are signed by the government only.
A contract modification (usually called a "mod") is a formal amendment to a signed government contract. Modifications happen frequently — a typical multi-year contract may have 5-30 mods over its lifecycle.
Types: - Bilateral modification (SF 30): both parties sign. Used when the change adjusts price, scope, or terms in a way that requires mutual agreement. Requires equitable adjustment negotiation if the change affects cost or schedule. - Unilateral modification: signed only by the contracting officer. Used for actions the government has the contractual right to take, like exercising an option period, funding an incremental increase, or making an administrative correction. - Change order (FAR 43.201): a specific type of unilateral modification directing the contractor to make a change within the general scope. The contractor must comply and can request an equitable adjustment for the cost and time impact.
Common modification types: - Option exercise: extends the contract into the next base or option period. - Funding modification: adds incremental funding to an incrementally funded contract without changing scope. - Scope modification: adds or removes work. If additional scope is significant, may require new competition (avoiding "out-of-scope" issues that can trigger bid protests). - Administrative modification: corrects clerical errors, updates contact information, changes payment terms. - No-cost time extension: extends the period of performance without additional cost. - Termination modification: partial termination for convenience, discontinuing a portion of work.
Why modifications matter to vendors: (1) Your revenue on a contract depends on both the base award AND the modifications. Track mod history when researching an incumbent. (2) You have a right to equitable adjustment for many change orders — read FAR Part 43 and your contract's Changes clause. (3) Sole-source mods that add substantial new scope to an existing contract can be protested by competitors as improper sole-source awards.
Where to find modifications: FPDS-NG and USASpending.gov show all federal contract actions including modifications. Each action has a "modification number" and reason code. State and local mod visibility is less consistent — check the issuing agency's procurement records.