For ACOs

This page contains information for Accountable Care Organizations (ACOs) applying to and participating in the Shared Savings Program, including an overview of the agreement period, as well as application resources.

Application submission activities and certain program operations are conducted in the ACO Management System (ACO-MS).

Program Participation Information

For agreement periods beginning on July 1, 2019, and in subsequent years, ACOs agree to participate in the Shared Savings Program for a period of no less than five years, known as the agreement period. The agreement period is made up of performance years that follow similar operational processes.

ACOs may participate in the Shared Savings Program for agreement periods of at least five years, under one of two tracks: the BASIC track (which includes a glide path for eligible ACOs), or the ENHANCED track, which offers the highest level of risk and potential reward. ACOs participating in the BASIC track’s glide path may begin under a one-sided model and progress through incremental levels of increasing risk and potential reward.

For more information about the participation options available to ACOs, refer to the About the Program webpage.

Over the course of an agreement period, ACOs:

  • Coordinate care for beneficiaries, measure and improve quality, and publicly report performance results;
  • Prepare for the next performance year by making sure contact information is current in CMS systems, maintaining their ACO Participant List and Skilled Nursing Facility (SNF) Affiliate List (if applicable), and completing the Annual Certification process; and
  • Receive annual financial and quality performance results.

ACOs must have at least 5,000 Medicare fee-for-service (FFS) beneficiaries assigned to their ACO in each benchmark year to be eligible for participation in the Shared Savings Program.

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Information for Applicants

All ACO applicants should reference the following resources.

Application Types & Timeline

Find sample applications and related resources.                                                                                   

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Application Toolkit

Find the Application Reference Manual and guidance to help ACOs apply to the Shared Savings Program.

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For application questions, visit the Contact Information webpage.

Program Data

CMS makes data on Shared Savings Program ACOs publicly available through several resources, including On this page, find more information related to Shared Savings Program ACO participation and performance.

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CMS ACO Learning System

Since 2012, CMS has supported ACOs in their efforts to improve the delivery of care for their assigned beneficiary populations through model-specific learning systems. These learning systems provide ACOs with a forum in which they can collaborate with and learn from one another. Visit the CMS Innovation Center ACOs webpage for the most current Toolkits and Case Studies.

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Page Last Modified:
12/01/2021 08:00 PM