Appropriate Use Criteria Program

What is the Appropriate Use Criteria Program?

Congress established the Appropriate Use Criteria (AUC) Program to reduce the inappropriate or unnecessary ordering and performing of outpatient advanced diagnostic imaging services. In addition, the goal of this Program is to ensure providers who order outpatient imaging services for Medicare patients have medical necessity to do so. In essence, the AUC Program establishes a prior authorization like plan for outpatient advanced diagnostic imaging services. Although the AUC Program penalty phase has been delayed by the Centers for Medicare and Medicaid Services (CMS), it’s important to act now to prepare for this future requirement.

AUC Program Timeline

The AUC Program was established by Congress in 2014, but full implementation has been delayed due to the COVID-19 Public Health Emergency (PHE). The Program is currently in an education and operations testing period that launched January 2020. It was expected to enter the penalty phase on January 1, 2023; however, in early July 2022, CMS posted on its website that the penalty phase will not begin on January 1, 2023, even if the COVID-19 PHE ends in 2022. Currently, a start date for the penalty phase is unknown.

Who AUC Impacts?

The Program impacts two key groups whose claims are paid under the physician fee schedule, hospital outpatient prospective payment system or ambulatory surgical center payment system, including:

  1. All providers who order advanced diagnostic imaging services
  2. Providers and facilities that furnish advanced diagnostic imaging services in a physician’s office, hospital outpatient department (including the emergency department), an ambulatory surgical center or an independent diagnostic testing facility (IDTF)

How AUC Works?

At the time a provider orders an advanced diagnostic imaging service for a Medicare patient, the provider must consult a CMS-approved Clinical Decision Support Mechanism (CDSM).  

  • A CDSM is an interactive, electronic tool where providers can access AUC criteria. See the checklist below for more details. Providers may also delegate this task but only to clinical staff acting under the provider’s direction.
  • The CDSM also provides a determination of whether the imaging order:
    • Adheres to AUC
    • Does not adhere to AUC
    • If there is no AUC applicable (for example, no AUC is available to address the patient’s clinical condition)

For providers to receive payment, they must include AUC consultation information on the claim to send to Medicare. Each claim must include the CDSM consulted by the provider (a G-code), an HCPCs modifier, which indicates whether the ordered service adhered to the AUC or not, and the NPI of the ordering provider.

There are certain exceptions to consulting and reporting, including emergency services, inpatients where payment is made under Medicare Part A and significant hardships on the ordering provider (i.e., insufficient internet access, EHR or CDSM vendor issues and extreme and uncontrollable circumstances, which CMS will likely review on a case-by-case basis).

Implications for Not Following the AUC Requirements

Any Medicare claim submitted without the required consultation information (noted above) will be denied or returned to the provider who would have to resubmit including the AUC required information in the claim. In addition, CMS states that providers whose ordering patterns are considered “outliers” (i.e., orders are noncompliant with the AUC Program) will be subject to mandatory prior authorization. To date, CMS has not provided information on its methodology for determining outliers.

Key Considerations for Providers:

  • Unlike prior authorization requirements for commercial insurance, there is no “hard-stop” when ordering an exam under the AUC Program if the order doesn’t “fit” within the requirements.
  • Under the AUC Program, if the provider consults with a CMS approved CDSM tool and correctly documents that on the claim, the provider can proceed with ordering the imaging and receive payment on that claim even if the order does not adhere to the AUC Program. 

Act Now to Help Ensure Your Organization is Prepared for the AUC Program

There is growing attention to cost containment and appropriate use for outpatient services. Although CMS delayed their penalty phase for a January 1, 2023, go-live, there are a lot of steps to take to prepare for this requirement.

Put processes in place now to align with the AUC program requirements.

AUC Implementation Checklist:

  • Review the AUC program requirements and identify which stakeholders, service lines and vendors will be affected (e.g., IT, clinical staff, internal staff, outside providers).
    • Select a CMS-approved CDSM tool. Approved CDSM tools can be either stand-alone, web-based (free options) or integrated into an EHR system. (Ask your EHR vendor for their recommended CDSM.) Planning now can help with future budgeting if there is a cost associated with your tool.
    • If an EHR-integrated tool is selected, work with your EHR vendor on implementation and testing. 
    • If a stand-alone CDSM tool is selected, integrate it with the host (e.g., EHR) system.
    • Create and provide training to ordering providers and their clinical staff on the AUC program and its requirements, as well as how to follow operational processes and access the CDSM for AUC consultation.
    • Ensure providers and billers appropriately report AUC requirements on Medicare claims.
  • Build in time to test and review for compliance and identify opportunities for additional training/education.
    • Conduct internal audits of your ordering providers; this can be done during the testing phase.
    • Ascertain, by provider, what percentage of orders are deemed by the CDSM as “inappropriate” to help avoid be classified as an “outlier.”
    • Determine if there are discernable patterns in terms of the types of medical conditions or tests that are deemed inappropriate and educate your providers on the results.

Keep on Your Radar:

  • Consider conversations with your commercial payors to determine if they will be leveraging AUC consultation as part of their business policy.
  • Consider how outside imaging orders will be handled. The ordering provider must provide AUC documentation, not the furnishing provider.

We will continue to keep you updated on any AUC developments.


  • CMS website for the Appropriate Use Criteria Program
  • MLN Matters Article MM11268 includes a code list of HCPCs and a list of modifiers established for the AUC Program.
  • MLN Matters SE20002 provides guidance for processing institutional claims in the AUC Program.
  • CMS’ online list of qualified CDSMs and their corresponding G-codes