; and (2) include a clause in the contract requiring that the prime contractor shall submit to the agency a written notification of any subcontractor substituted after the award of the contract for a subcontractor so listed, along with an updated estimate for the cost of performing the work associated with the substituted subcontractor. (b) Modification to contract In the case of a construction contract covered by subsection (a), if the prime contractor notifies the agency of a substituted subcontractor under subsection (a)(2) and there is a significant difference in the cost of performing the work associated with the substituted subcontractor, the contracting officer for the contract may modify the contract to take into account the substitution of subcontractor, including modification of the amount of the contract. (c) Agency defined In this Act, the term agency has the meaning provided the term executive agency by section 133 of title 41, United States Code, except the term does not include the Department of Defense or any military department, but such term shall include the United States Army Corps of Engineers. (d) Revision of Federal Acquisition Regulation (1) In general Not later than 180 days after the date of the enactment of this section, the Federal Acquisition Regulation shall be revised to provide for the implementation of this section. (2) Notice and Comment There shall be provided a public notice and comment period of not less than 60 days. (3) Final rule Any final rule promulgated pursuant to this subsection shall take effect 30 days after the date on which the final rule is published in the Federal Register. (e) Effective date This Act shall apply with respect to contracts awarded on or after the date occurring 180 days after the date of the enactment of this Act.