; or (2) enter into a contract or extend or renew a contract with an entity described in subsection (a)(2). (c) Effective dates (1) Certain entities With respect to the biotechnology companies of concern covered by subsection (f)(2)(A), the prohibitions under subsections (a) and (b) shall take effect 60 days after the issuance of the implementing guidance in subsection (f)(3) or the expiration of the deadline set forth in subsection (f)(3), whichever occurs first. (2) Other entities With respect to the biotechnology companies of concern covered by subsection (f)(2)(B), the prohibitions under subsections (a) and (b) shall take effect 180 days after the issuance of the implementing guidance in subsection (f)(3) . (d) Waiver authorities (1) Specific biotechnology exception (A) Waiver The head of an executive agency may waive the prohibition under subsection (a) and (b) on a case-by-case basis— (i) with the approval of the Director of the Office of Management and Budget, in consultation with the Federal Acquisition Security Council and the Secretary of Defense