42 C.F.R. § 425.226
(a) General. This section applies to ACOs in agreement periods beginning on July 1, 2019, and in subsequent years. Before the start of a performance year, an ACO may make elections related to its participation in the Shared Savings Program, as specified in this section, effective at the start of the applicable performance year and for the remaining years of the agreement period, unless superseded by a later election in accordance with this section.
(1) Selection of beneficiary assignment methodology. An ACO may select the assignment methodology that CMS employs for assignment of beneficiaries under subpart E of this part. An ACO may select either of the following:
(2) Selection of BASIC track level. An ACO participating under the BASIC track in the glide path may select a higher level of risk and potential reward, as provided in this section.
(ii) An ACO transitioning to a higher level of risk and potential reward under paragraph (a)(2)(i) of this section must meet all requirements to participate under the selected level of performance-based risk, including both of the following:
(b) Election procedures.
[83 FR 68066, Dec. 31, 2018]