FAR 52.243-4—Changes.
Plain-English Summary
FAR 52.243-4, Changes, is the standard changes clause for many fixed-price construction and other non-commercial contracts. It gives the Contracting Officer authority to direct certain unilateral changes within the general scope of the contract, including changes to specifications, drawings, designs, methods or manner of performance, Government-furnished property or services, and acceleration. It also covers constructive changes—meaning written or oral orders, instructions, interpretations, or determinations that effectively change the work even if they are not labeled a formal change order—so long as the contractor gives timely written notice identifying the order and stating that it is being treated as a change. The clause explains when the contractor is entitled to an equitable adjustment for increased or decreased cost or time, how defective specifications are handled, the contractor’s duty to submit a proposal for adjustment within 30 days unless extended, the ability to include that proposal in the notice for a constructive change, and the absolute bar on claims asserted after final payment. In practice, this clause is the main mechanism for managing scope changes during performance while preserving the contractor’s right to be paid for added work or time and protecting the Government from unauthorized or stale claims.
Key Rules
CO may direct in-scope changes
The Contracting Officer may issue a written change order at any time, without notice to sureties, for changes within the general scope of the contract. The clause specifically allows changes to specifications, drawings, designs, performance methods, Government-furnished property or services, and acceleration.
Constructive changes count too
A written or oral order, instruction, interpretation, or determination that causes a change is treated as a change order if the contractor gives written notice stating the date, circumstances, source, and that it regards the direction as a change order. This protects contractors from losing adjustment rights when the Government changes the work informally.
No adjustment without clause basis
Except as allowed by the clause, no order, statement, or conduct by the Contracting Officer is treated as a change or as a basis for an equitable adjustment. Contractors must tie their request to this clause and show that the Government action actually changed the work.
Equitable adjustment is required
If a change increases or decreases cost or time, the Contracting Officer must make an equitable adjustment and modify the contract in writing. For defective specifications attributable to the Government, the adjustment includes reasonably incurred increased costs from trying to comply with the defective requirements.
Notice timing limits recovery
For constructive changes under paragraph (b), no adjustment is allowed for costs incurred more than 20 days before the contractor gives the required written notice, except for defective specifications. Timely notice is critical to preserve recovery for earlier costs.
Contractor must submit proposal promptly
The contractor must assert its right to an adjustment within 30 days after receiving a written change order or giving notice of a constructive change, unless the Government extends the period. The proposal must describe the general nature and amount of the adjustment, and it may be included in the notice itself.
Final payment cuts off claims
No proposal for equitable adjustment may be allowed if it is asserted after final payment under the contract. Contractors must preserve and submit claims before final payment or risk losing the right entirely.
Responsibilities
Contracting Officer
Issue written change orders only within the general scope of the contract; evaluate whether contractor notice and proposal are timely and sufficient; negotiate and execute equitable adjustments in writing; recognize and process defective-specification adjustments; and extend the 30-day proposal period when appropriate.
Contractor
Comply with authorized change orders; promptly identify and notify the Contracting Officer of constructive changes in writing; state the date, circumstances, and source of the direction and that it is being treated as a change; submit a written proposal for equitable adjustment within 30 days unless extended; and ensure any claim is asserted before final payment.
Government technical personnel / COR
Avoid giving informal directions that could create constructive changes; route scope, design, or performance issues through the Contracting Officer; and document communications carefully so the contract administration record reflects whether an action is a change or merely clarification.
Sureties
No direct action is required under the clause, but they are not entitled to prior notice before the Contracting Officer issues a change order. They remain relevant because changes can affect bonded work and project risk.
Agency
Follow agency procedures that may vary the 30-day period; train personnel on change-order authority and constructive-change risk; and maintain contract administration controls to ensure changes are documented and priced properly.
Practical Implications
This clause is the primary tool for handling scope growth or design revisions without turning every change into a dispute, but only if the parties document the change correctly and quickly.
Contractors should never rely on oral direction alone; if the Government’s instruction changes the work, written notice should be sent immediately to preserve entitlement and start the adjustment process.
The 20-day lookback for constructive changes is a common trap: delay in notice can wipe out recovery for costs incurred before notice, even when the Government caused the change.
Defective specifications are treated more favorably to contractors, but the contractor still must show the Government was responsible and that the extra costs were reasonably incurred in trying to comply.
Final payment is a hard stop. If an equitable adjustment has not been asserted before final payment, the contractor generally loses the right to recover under this clause.
Official Regulatory Text
As prescribed in 43.205 (d) , insert the following clause: The 30-day period may be varied according to agency procedures. Changes (June 2007) (a) The Contracting Officer may, at any time, without notice to the sureties, if any, by written order designated or indicated to be a change order, make changes in the work within the general scope of the contract, including changes- (1) In the specifications (including drawings and designs); (2) In the method or manner of performance of the work; (3) In the Government-furnished property or services; or (4) Directing acceleration in the performance of the work. (b) Any other written or oral order (which, as used in this paragraph (b), includes direction, instruction, interpretation, or determination) from the Contracting Officer that causes a change shall be treated as a change order under this clause; Provided, that the Contractor gives the Contracting Officer written notice stating- (1) The date, circumstances, and source of the order; and (2) That the Contractor regards the order as a change order. (c) Except as provided in this clause, no order, statement, or conduct of the Contracting Officer shall be treated as a change under this clause or entitle the Contractor to an equitable adjustment. (d) If any change under this clause causes an increase or decrease in the Contractor’s cost of, or the time required for, the performance of any part of the work under this contract, whether or not changed by any such order, the Contracting Officer shall make an equitable adjustment and modify the contract in writing. However, except for an adjustment based on defective specifications, no adjustment for any change under paragraph (b) of this clause shall be made for any costs incurred more than 20 days before the Contractor gives written notice as required. In the case of defective specifications for which the Government is responsible, the equitable adjustment shall include any increased cost reasonably incurred by the Contractor in attempting to comply with the defective specifications. (e) The Contractor must assert its right to an adjustment under this clause within 30 days after (1) receipt of a written change order under paragraph (a) of this clause or (2) the furnishing of a written notice under paragraph (b) of this clause, by submitting to the Contracting Officer a written statement describing the general nature and amount of the proposal, unless this period is extended by the Government. The statement of proposal for adjustment may be included in the notice under paragraph (b) of this clause. (f) No proposal by the Contractor for an equitable adjustment shall be allowed if asserted after final payment under this contract. (End of clause)