Section 425.220 - Termination of the participation agreement by the ACO(a)Notice of termination. An ACO must provide at least 30 days advance written notice to CMS and its ACO participants of its decision to terminate the participation agreement and the effective date of its termination. 76 FR 67973 , Nov. 2, 2011, as amended at 80 FR 32839 , June 9, 2015; 83 FR 68064 , Dec. 31, 2018