Congress has mandated that ordering providers show that they consulted appropriate use criteria (AUC) when ordering advanced imaging (MR, CT, PET, NM) for their Medicare patients. The Centers for Medicare & Medicaid Services (CMS) has proposed an extension of the educational and testing period for the Medicare AUC program through 2022. 

RadNet will be ready to accept AUC information during the educational and testing period.

What’s the latest?

The educational and operations testing period for the AUC program is proposed by CMS to extend through CY 2022. There are no payment consequences associated with the AUC program during CY 2021 and CY 2022. CMS is encouraging stakeholders to use this period to learn, test, and prepare for the AUC program. The necessary G-codes and modifiers corresponding to an AUC consultaton continue to be:

1. G-Code

Indicates the qCDSM, such as NDSC’s CareSelect¹, that was consulted prior to placing the order.

2. Modifier

Indicates whether the order:

  • adhered to AUC, did not adhere to AUC, or AUC was not applicable

  • Lacked AUC consultation information

  • Qualified for an exception

3. NPI

The national provider identifier of the ordering professional (the referrer).


For the ordering provider’s edification, the qCDSM returns a score to indicate how closely the ordered exam corresponds to AUC. Depending on the qCDSM, that score is shown as a color (red, yellow, green), a number (1-9), or letter.

Any exceptions?

Ordering professionals are exempt from consulting and reporting AUC only under these circumstances:

  • Emergency services in life-threatening situations

  • Public health emergencies (proposed)

  • Services for an inpatient for whom payment is made under Medicare Part A, or for Medicare Advantage payments

  • A hardship exception, such as natural disasters, no broadband internet, or EHR system failures.

What is RadNet's role?

RadNets AUC team will soon be ready to accept AUC information, if provided by ordering clinicians, for our 340+ imaging centers and for our hospital partnerships. Billing, services, and management will all be affected by this mandate. 

The RadNet AUC team understands and can address all aspects of the law. We stand ready to assist RadNets referring physicians as they make adjustments to meet these new consultation requirements. 

† National Decision Support Company’s CareSelect is used here only as an example; CMS qualifies all Clinical Decision Support Mechanisms.


Get the full scoop on AUC.

Presented by:
Michael R. Mabry
Director, Public Policy and Economic Analysis

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Frequently Asked Questions

What happens if I don’t provide AUC consultation information?

The “MH” modifier will be reported on a Medicare claim for an order without AUC consultation information.

What about non-advanced diagnostic exams? Do I need to consult AUC?

Ordering professionals are not required to consult AUC for non-advanced diagnostic exams. The PAMA legislation mandates that AUC be consulted for all advanced diagnostic imaging services.

When does all this start?

The educational and operations testing period for the CMS AUC program has been proposed to extend through December 31, 2022. During that testing period, advanced imaging claims will be paid whether or not they correctly include AUC consultation information, but all ordering and rendering providers are strongly encouraged to participate.

My EMR doesn’t have an interface to a qCDSM. What are my options?

There are three free portals offered which integrate a qCDSM that providers can use to consult AUC. These are:

CMS Also has a list of 17 other qCDSMs which are fee-structured. Click here to go to that list.

What exactly must the ordering professional include on a claim to Medicare?

Medicare claims must include

  • the National Provider Identifier of the ordering professional.

  • the G-code generated from the qualified Clinical Decision Support Mechanism that was consulted

  • the modifier which states whether the ordered procedure adhered to the AUC, did not adhere, or was not applicable to the requirement. 

Will reports be different as a result of AUC?

No. Radiology reports are unaffected by AUC, with no change in lexicon or approach.

Will AUC apply when Medicare is the secondary insurance?

At this time AUC only applies when Medicare is the primary insurance.

What happens if an ordering professional orders outside of a green adherence?

Right now, nothing. There is no hard stop in 2021 or 2022, as it is proposed to be an operational and testing period. CMS is asking ordering professionals to try to consult AUC during the educational and testing year. Ordering professionals can continue with the order, however CMS has the authority to identify professionals who have outlier ordering patterns in the years subsequent to AUC going live. Professionals identified as outliers may be subject to prior authorization.

What information is required from the ordering professional to complete the AUC consult?

The following information is required: the patients age, the patients gender, signs and symptoms, and the test being ordered.

Does the ordering provider still have to consult AUC if they do not participate with Medicare but want to refer a Medicare PT?

Yes, the non-participating ordering practice/provider will still have to perform an AUC consultation, as the claim must have AUC information attached when it is submitted to CDS.

Do Medicare Advantage plans have to comply with the CMS AUC mandate?

At this time,  AUC only applies to traditional Medicare Part B.

What happens if I do not provide AUC consultation information?

Starting January 1, 2023, rendering providers will not receive payment for the procedure without a documented consult, according to the latest proposal from CMS. The law does not mandate ordering providers strictly adhere to the AUC, just that AUC is consulted. There is no “hard stop” to the ordering process. Providers that do comply can receive Merit-Based Incentive Payment System (MIPS) and Improvement Activity points, as well as the Promoting Interoperability bonus from CMS.

Can imaging providers perform AUC on behalf of the ordering physician?

No, the mandate states that the ordering professional must perform the AUC consultation.

Who is allowed to perform the qCDSM consultation?

The consultation can be performed by the ordering clinician or a delegate, under the clinicians direction, who has sufficient clinical knowledge, qCDSM expertise, and the means to communicate the AUC results to the ordering clinician. The AUC information (G-code and modifier) must accompany the order for the advanced diagnostic imaging study.

I don’t understand all the requirements. What should I do?

RadNet has all the resources you need. We are ready with education and outreach to help you gain the knowledge you need to comply with the mandate and feel comfortable with the changes. To read about AUC, you can also click here.