the Clayton Act ( 15 U.S.C. 12(a) ). . (b) Effective date Section 2729B of the Public Health Service Act (as added by section 301 and amended by subsection (a)) shall apply with respect to any contract entered into on or after the date that is 18 months after the date of enactment of this Act. With respect to an applicable contract that is in effect on the date of enactment of this Act, such section 2729B shall apply on the earlier of the date of renewal of such contract or 3 years after such date of enactment. 307. Repealing eligibility of certain ACOs (a) In general Section 1899(b)(1) of the Social Security Act ( 42 U.S.C. 1395jjj(b)(1) ) is amended by striking subparagraphs (C) through (E). (b) Effective date The amendment made by subsection (a) shall take effect on January 1, 2021. 308. Repeal of health care reform provisions limiting Medicare exception to the prohibition on certain physician referrals for hospitals Sections 6001 and 10601 of the Patient Protection and Affordable Care Act ( Public Law 111–148