42 CFR § 425.100 - General.
(a) Under the Shared Savings Program, ACO participants may work together to manage and coordinate care for Medicare fee-for-service beneficiaries through an ACO that meets the criteria specified in this part. The ACO must become accountable for the quality, cost, and overall care of the Medicare fee-for-service beneficiaries assigned to the ACO.
(b) ACOs that meet or exceed a minimum savings rate established under § 425.604, § 425.605, § 425.606, § 425.609 or § 425.610, meet the minimum quality performance standards established under § 425.500, and otherwise maintain their eligibility to participate in the Shared Savings Program under this part are eligible to receive payments for shared savings under subpart G.
(c) ACOs that operate under a two-sided model and meet or exceed a minimum loss rate established under § 425.605, § 425.606, § 425.609 or § 425.610 must share losses with the Medicare program under subpart G of the part.