Skip to main content

Medicare-Only ACOs new to Vermont

In 2016, the Green Mountain Care Board was given the authority to develop rules and standards to regulate Accountable Care Organizations (ACOs) through Vermont’s Act 113: ‘An act relating to implementing an all-payer model and oversight of accountable care organizations.’ The GMCB has adopted Rule 5.000: Oversight of Accountable Care Organizations, which establishes standards and processes the GMCB will use to certify ACOs and annually review, modify, and approve their budgets, and mechanisms by which the GMCB will monitor and oversee the activities performance of ACOs. Read more our mission here and about ACO oversight here.

Any ACO with Vermont providers in its network is subject to GMCB regulation. 

Medicare-only ACO regulation 

Medicare-only ACO flow chart explaining that budget review is required and certification is not. Standards for budget review depends on size of ACO.

Medicare-only ACOs operating in Vermont, regardless of size, are required by Rule 5.000 to have their budgets reviewed and approved annually by the GMCB.  

Certification is not currently required for Medicare-only ACOs to operate in Vermont.  

Medicare-only ACO timeline of events 

  • July 1st - Budget review and guidance released 
  • October 1st – ACO budget submission due 
  • October - November 
    • GMCB reviews submissions 
    • ACO presents proposed budget at public hearings 
    • ACO and payers present prior year results 
  • December 
    • Board publicly deliberates to approve or modify budgets 
  • January 1st – ACO program year begins 
  • March – April  
    • ACO submits prior year actuals 
    • ACO submits final contracts and attribution for current program year; total ACO budget is updated 
  • Ongoing  
    • GMCB ordered monitoring and reporting 
    • Prior year financial and quality performance results 


For more information about Medicare-only ACOs currently operating in Vermont and the most recent Medicare-only guidance click here

Next steps 

ACOs planning to operate in Vermont should reach out to the Green Mountain Care Boards ACO Oversight team at for more information.