48 CFR §42.1303

1. (a)Stop-work orders may be used, when appropriate, in any negotiated fixed-price or cost-reimbursement supply, research and development, or service contract if work stoppage may be required for reasons such as advancement in the state-of-the-art, production or engineering breakthroughs, or realignment of programs.
2. (b)Generally, a stop-work order will be issued only if it is advisable to suspend work pending a decision by the Government and a supplemental agreement providing for the suspension is not feasible. Issuance of a stop-work order shall be approved at a level higher than the contracting officer. Stop-work orders shall not be used in place of a termination notice after a decision to terminate has been made.
3. (c)Stop-work orders should include—
   1. (1)A description of the work to be suspended;
   2. (2)Instructions concerning the contractor's issuance of further orders for materials or services;
   3. (3)Guidance to the contractor on action to be taken on any subcontracts; and
   4. (4)Other suggestions to the contractor for minimizing costs.
4. (d)Promptly after issuing the stop-work order, the contracting officer should discuss the stop-work order with the contractor and modify the order, if necessary, in light of the discussion.
5. (e)As soon as feasible after a stop-work order is issued, but before its expiration, the contracting officer shall take appropriate action to—
   1. (1)Terminate the contract;
   2. (2)Cancel the stop-work order (any cancellation of a stop-work order shall be subject to the same approvals as were required for its issuance); or
   3. (3)Extend the period of the stop-work order if it is necessary and if the contractor agrees (any extension of the stop-work order shall be by a supplemental agreement).