Find guidance and specifications pertaining to Accountable Care Organizations (ACOs) applying to and/or participating in the Medicare Shared Savings Program (Shared Savings Program).

• Application Guidance
• ACO Participant List and Participant Agreement Guidance
• SNF 3-Day Rule Waiver Guidance
• Beneficiary Incentive Program Guidance
• ACO Banking Form Instructions
• Repayment Mechanism Arrangements Guidance
• ACO Compliance Plan Guidance
• Data and Report Sharing
• Financial and Beneficiary Assignment Specifications
• Quality Resources and Information
• Primary Service Area Calculation
• Requesting Technical Assistance and Reconsideration Review Guidance

Application Guidance

The Application Toolkit provides quick access to guidance relevant to all application types. For more information about applying to the Shared Savings Program, refer to the Application Toolkit.

ACO Participant List and Participant Agreement Guidance

Participating ACOs may modify their ACO Participant List and associated agreements for the upcoming performance year during established timeframes. 

• ACO Participant List and Participant Agreement Guidance (Updated 5/14/2021) (PDF)
• Frequently asked questions about affiliating with an ACO as an “Other Entity (PDF),” instead of as an ACO participant

SNF 3-Day Rule Waiver Guidance

Participating ACOs approved for a Skilled Nursing Facility (SNF) 3-Day Rule Waiver may modify their SNF Affiliate List and associated agreements for the upcoming performance year during established timeframes. 

• Skilled Nursing Facility 3-Day Rule Waiver Guidance (Updated 5/14/2021) (PDF)

Beneficiary Incentive Program Guidance

Participating ACOs approved to establish and operate a Beneficiary Incentive Program (BIP) may provide an incentive payment with a value of up to $20 to each assigned beneficiary for each qualifying primary care service received.

• Beneficiary Incentive Program Guidance (Updated 5/12/2022) (PDF)

ACO Banking Form Instructions

Participating ACOs must maintain a current Electronic Funds Transfer Authorization Agreement (Form CMS-588) to receive shared savings.

• ACO Banking Form Instructions (Updated 5/18/2022) (PDF)

Repayment Mechanism Arrangements Guidance

ACOs electing to participate in two-sided risk must have the ability to pay all shared losses for which they may be liable. The Centers for Medicare & Medicaid Services (CMS) strongly encourages applicants to submit preliminary repayment mechanism documentation in Microsoft Word format for feedback. 

• Repayment Mechanism Arrangements Guidance (Updated 5/14/2021) (PDF)
  • Appendix A: Escrow Agreement Template (Updated 5/10/2021) (DOCX)
  • Appendix B: Escrow Agreement Amendment Sample (Updated 5/10/2021 (DOCX)
  • Appendix C: Letter of Credit Sample (Updated 5/10/2021) (DOCX)
  • Appendix D: Surety Bond Sample (Updated 5/10/2021) (DOCX)
  • Appendix E: Repayment Mechanism Documentation Cover Sheet (Updated 5/10/2021) (DOCX)

ACO Compliance Plan Guidance

To participate in the Shared Savings Program, each ACO must have a compliance plan in accordance with 42 CFR § 425.300.

• Compliance Plan Tip Sheet (PDF)

Data and Report Sharing

CMS provides ACOs with information on their assigned population and financial performance at the start of the agreement period and routinely during the performance year. ACOs must request to receive monthly Claim and Claim Line Feed (CCLF) files on Medicare fee-for-service (FFS) beneficiaries who have not declined to share their data.

• PY 2022 Shared Savings Program Report Templates (ZIP): CMS revises the format of the reports annually to account for changes in the program's regulations, and to incorporate ACOs' feedback on the reports including requests for additional data elements. Please check this file periodically for updates.

Financial and Beneficiary Assignment Specifications

Participating ACOs are encouraged to reference the program’s financial and beneficiary assignment specifications for detailed information on how the Shared Savings Program assigns beneficiaries to each ACO and calculates a historical financial benchmark from which to assess annual financial performance, and ultimately, eligibility for an earned shared savings payment.

Current Years Shared Savings and Losses and Assignment Methodology Specifications

ACOs participating under agreement periods beginning prior to July 1, 2019, that will be reconciled for Performance Year (PY) 2021 should refer to the benchmarking methodology described in Version 7 (PDF) and assignment sections described in Version 9 (PDF).  ACOs participating under agreement periods beginning on or after July 1, 2019 that will be reconciled for PY 2021 should refer to the benchmarking methodology and assignment sections described in Version 9 (PDF). All ACOs participating in PY 2022 should refer to Version 10 (PDF). For prior years information please reference the “Prior Years Shared Savings and Losses and Assignment Methodology Specifications” section further below.

• Shared Savings and Losses and Assignment Methodology, Specifications of Policies to Address the Public Health Emergency for COVID-19 (PDF): describes the changes and clarifications to Shared Savings Program policies, addressing the impact of the coronavirus disease 2019 (COVID-19) pandemic and the resulting PHE, that were finalized in the Calendar Year (CY) 2021 Physician Fee Schedule Final Rule (85 FR 84472).
• Shared Savings and Losses and Assignment Methodology Specifications Version 10 (PDF): incorporates changes to Shared Savings Program assignment policies outlined in the CY 2022 Physician Fee Schedule Final Rule (86 FR 65524) that are applicable for PY 2022.
• Shared Savings and Losses and Assignment Methodology Specifications Version 9 (PDF): incorporates changes to Shared Savings Program policies outlined in the CY 2021 Physician Fee Schedule Final Rule (85 FR 84472), including the beneficiary assignment methodology and the quality performance standard applicable for PYs beginning on January 1, 2021. Note: Version 9 of the Specifications is relevant to ACOs with agreement periods starting on or after July 1, 2019, except as otherwise noted. 
• Shared Savings and Losses and Assignment Methodology Specifications Version 7 (PDF): incorporates the changes outlined in the CY 2019 Physician Fee Schedule Final Rule (83 FR 59452) that are applicable for PY 2019 for ACOs participating as of January 1, 2019. 

Prior Years Shared Savings and Losses and Assignment Methodology Specifications

• Shared Savings and Losses and Assignment Methodology Specifications Version 8 (PDF)
• Shared Savings and Losses and Assignment Methodology Specifications Version 6 (PDF)
• Shared Savings and Losses and Assignment Methodology Specifications Version 5 (PDF)
• Shared Savings and Losses and Assignment Methodology Specifications Version 4 (PDF)
• Shared Savings and Losses and Assignment Methodology Specifications Version 3 (PDF)

Quality Resources and Information

Quality Measurement

Participating ACOs must report quality data to CMS after the close of every performance year to be eligible to share in any earned shared savings and to avoid sharing losses at the maximum level. CMS measures every ACO’s quality performance using standard methods.

To learn more about the Shared Savings Program quality measurement and the Alternative Payment Model (APM) Performance Pathway (APP) for PY 2021, refer to:

• APM Performance Pathway (APP) Toolkit (ZIP): Contains resources designed to help Shared Savings Program ACOs and their Merit-based Incentive Payment System (MIPS) eligible clinicians successfully participate in the APP, including:  
  • 2021 APM Performance Pathway for MIPS APM Participants Fact Sheet
  • APM Performance Pathway for Shared Savings Program Accountable Care Organizations (ACOs) User Guide
  • APM Performance Pathway for MIPS APM Participants Infographic
  • 2021 APM Performance Pathway Quick Start Guide
  • 2021 APM Performance Pathway Reporting Scenarios
  • 2021 APM Performance Pathway Scoring Guide 
• APM Performance Pathway webpage

To learn more about the Shared Savings Program quality measurement for PY 2021, refer to:

• Performance Year 2021 APM Performance Pathway: CMS Web Interface Measure Benchmarks for ACOs: This document describes methods for calculating the CMS Web Interface measure benchmarks for ACOs reporting the CMS Web Interface measures for the 2021 performance year. The benchmarks for the 10 CMS Web Interface measures are displayed in Appendix A of this document.
• 2021 CMS Web Interface Measure Specifications and Supporting Documents: Provides comprehensive descriptions of the 2021 CMS Web Interface measures for the MIPS Quality performance category
• 2021 Hospital-Wide All-Cause Unplanned Readmission Measure: Provides details on the measure development and final specifications for the Hospital-Wide, 30-Day, All-Cause Unplanned Readmission Rate for MIPS Groups.
• 2021 Risk Standardized, All-Cause Unplanned Admissions for Multiple Chronic Condition (MCCs) for ACOs: Provides the rate of risk-standardized acute, unplanned hospital admissions among Medicare Fee-for-Service (FFS) beneficiaries 65 years and older with MCCs who are assigned to an ACO.
• Quality Payment Program (QPP) Resource Library
  • 2021 QPP Final Rule Resources (ZIP)
  • 2021 MIPS Quality Benchmarks (ZIP)
  • 2021 CAHPS for MIPS Overview Fact Sheet

Prior Years Quality Documentation

• 2020 ACO Quality Reporting Documentation (ZIP)
• 2019 ACO Quality Reporting Documentation (ZIP) 
• 2018 ACO Quality Reporting Documentation (ZIP) 
• 2017 ACO Quality Reporting Documentation (ZIP)
• 2016 ACO Quality Reporting Documentation (ZIP)
• 2015 ACO Quality Reporting Documentation (ZIP)
• 2014 ACO Quality Reporting Documentation (ZIP)
• 2013 ACO Quality Reporting Documentation (ZIP)
• 2012 ACO Quality Reporting Documentation (ZIP)

Quality Measurement Performance Program Interactions Resources 

For more information on interactions between the Shared Savings Program and other CMS initiatives, please reference:

• Interaction with Other Medicare Initiatives: Provides an overview of how the QPP and other CMS Innovation Center initiatives intersect with the Shared Savings Program quality measurement.
• QPP Resource Library: Presents QPP resources, including fact sheets describing the interaction between the Shared Savings Program and the QPP.

Primary Service Area Calculation 

CMS makes data available to applicants to allow them to calculate their share of services in each applicable primary service area as described by the Antitrust Enforcement Policy.

• Calculating Your Primary Service Areas Guidance (DOCX) (PDF)

Requesting Technical Assistance and Reconsideration Review Guidance 

ACOs may request an appeal of an initial determination by CMS in limited circumstances.

• Requesting Technical Assistance and Reconsideration Review Guidance (Updated 5/14/2021) (PDF)

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