; and (2) in item (bb)— (A) by striking 75 percent and inserting the applicable percent ; and (B) by striking 50 percent and inserting the percent that is 10 percentage points less than the applicable percent . 4 Study on alternative payment models and Medicare Advantage Not later than 18 months after the date of enactment of this Act, the Comptroller General of the United States shall conduct a study and submit to the appropriate committees of Congress a report evaluating the benefits and flexibilities provided to support alternative payment models (as defined under section 414.1305 of title 42, Code of Federal Regulations (or a successor regulation)) and Medicare Advantage organizations (as defined in section 1859(a)(1) of the Social Security Act ( 42 U.S.C. 1395w–28(a)(1) )). The objective of such study and report shall be to better understand the effect of different policies under the Medicare program under title XVIII of the Social Security Act ( 42 U.S.C. 1395 et seq. ) with respect to such models and organizations on different types of beneficiaries and participating providers, including specialty, safety net, small practice, and rural providers, with the goal of identifying areas to enhance alignment between such policies and benchmarks, including through mechanisms that could facilitate greater alignment in such policies and benchmarks and to encourage the adoption of value-based arrangements across payers or that could otherwise increase parity in the flexibilities available to alternative payment models and Medicare Advantage organizations under the Medicare program.