Is your practice still attaching AUC codes to imaging claims that Medicare no longer requires? It’s a fair question, since the Appropriate Use Criteria program has gone through more delays and reversals than almost any other Medicare initiative. As of January 1, 2024, CMS directed providers and suppliers to stop including AUC consultation information on Medicare fee-for-service claims, reversing years of build-up toward a program that was originally supposed to reach full enforcement back in 2022.
Medicare AUC compliance in Athenahealth today isn’t about correctly formatting G-codes on every imaging claim anymore. It’s about understanding what’s actually still required, what’s paused, and what could return, since the underlying law behind this program was never repealed.
This guide explains what the AUC program is, where it currently stands, how CDSM G-codes worked while reporting was active, and which imaging billing requirements are still very much in effect, including the ordering physician NPI rules that have nothing to do with AUC at all.
What Is the Medicare AUC Program?
The Appropriate Use Criteria program was established under Section 218(b) of the Protecting Access to Medicare Act (PAMA) of 2014. It requires ordering physicians to consult a qualified Clinical Decision Support Mechanism, or CDSM, before ordering an advanced diagnostic imaging service for a Medicare beneficiary.
The program applies to advanced imaging services, including:
- MRI
- CT scans
- Nuclear medicine
- Positron emission tomography (PET)
It does not apply to X-rays, ultrasound, or fluoroscopy. The goal was to reduce inappropriate imaging orders by requiring clinicians to check evidence-based guidelines before ordering, with CMS eventually using the collected data to identify outlier ordering patterns.
Where the AUC Program Stands Today
The AUC program’s history is a story of repeated delays, and understanding that timeline matters for knowing what applies right now.
- 2014. PAMA establishes the AUC program in law.
- 2020. CMS begins an educational and operations testing period. Ordering providers are directed to consult a CDSM and report consultation data, but claims are not denied for missing this information.
- 2022 (planned). The program was originally slated to move to a payment penalty phase, where claims missing AUC reporting could be denied.
- 2024. CMS formally directs providers and suppliers to stop including AUC consultation codes on Medicare FFS claims. Claims with 2023 and 2024 dates of service using the old codes continue to process, but new claims no longer need them.
- Today. Claims-based AUC reporting remains paused. The statute has not been repealed, which means the program could be reinstated in a future rule.
Clinical Decision Support Mechanism G-Codes
Even though reporting is currently paused, understanding how the G-code system worked matters for any practice that may need to reactivate this workflow if CMS reinstates it.
How the G-Codes Functioned
CMS created HCPCS G-codes, ranging from G1000 through G1024, to identify which qualified CDSM an ordering physician consulted. The code was reported as a separate service line alongside the imaging procedure code, paired with a modifier (MA through MH, or QQ) indicating whether the order adhered to AUC, didn’t adhere, or had no applicable criteria.
Why This Infrastructure Still Matters
Many EHR systems, including certified modules connected to Athenahealth, still contain CDSM integration built during the active reporting period. Practices that disabled this workflow entirely may find it takes real setup time to reactivate if CMS brings back claims-based enforcement, so it’s worth confirming your CDSM access is still active even while reporting itself is paused.
Radiology and Cardiology Imaging Billing Rules
Beyond AUC specifically, radiology and cardiology imaging claims carry their own set of standing billing requirements that remain fully active regardless of the AUC pause.
Medical Necessity and Coverage Rules
Advanced imaging claims still require documentation supporting medical necessity, and Local Coverage Determinations published by Medicare Administrative Contractors define which diagnosis codes support coverage for a given imaging procedure. A claim with a diagnosis code outside the approved list for that procedure will be denied regardless of AUC status.
Professional and Technical Component Billing
Imaging services billed with modifier 26 (professional component) or TC (technical component) need to accurately reflect who interpreted the study versus who owns the equipment. Mismatched component billing between the ordering and interpreting provider remains a common source of denials in both radiology and cardiology imaging.
Attaching Ordering Physician NPI to Imaging Claims
This is a requirement that’s independent of the AUC program and remains fully in effect.
Why the Ordering NPI Requirement Still Applies
Medicare has long required the ordering or referring provider’s NPI to appear on imaging and diagnostic test claims, separate from any AUC reporting. This requirement traces back to broader Medicare ordering and referring provider edits, not to PAMA or the AUC statute, which is why it never paused alongside AUC reporting.
Common NPI Attachment Errors
A missing or incorrect ordering NPI is one of the most common reasons an otherwise clean imaging claim gets rejected before it even reaches adjudication. This typically happens when the ordering physician isn’t properly linked to the imaging order inside Athenahealth, or when a covering or referring provider’s NPI is used instead of the actual ordering physician’s.
AUC Requirements: Then vs Now
Understanding what changed helps billing teams avoid wasting effort on steps that are no longer required.
| Requirement | During Active Reporting (2020–2023) | Current Status (2024–present) |
| CDSM consultation | Required before ordering advanced imaging | No longer required to be reported on claims |
| G-codes (G1000–G1024) | Required on claim as separate line item | No longer required on new claims |
| AUC modifiers (MA–MH, QQ) | Required alongside G-codes | No longer required on new claims |
| Ordering physician NPI | Required | Still required |
| Medical necessity documentation | Required | Still required |
| Payment penalty for non-adherence | Never implemented | Not in effect |
Avoiding Medicare Diagnostic Test Rejections
With AUC reporting paused, most current imaging rejections trace back to the standing requirements that were never tied to AUC in the first place.
Reviewing Coverage Before Ordering
Checking the applicable Local Coverage Determination before ordering an advanced imaging study confirms the diagnosis code supports coverage for that specific procedure. This single check prevents a large share of avoidable imaging denials.
Confirming Ordering Data Before Submission
Before a claim is submitted, confirm the ordering physician’s NPI is correctly attached and that the imaging order in Athenahealth is properly linked to the correct ordering provider, not a covering physician or a different member of the care team.
Outsourced Compliance and Billing Audits
Given how often Medicare imaging rules have shifted over the past several years, ongoing compliance monitoring is difficult to sustain with internal resources alone.
Why This Work Suits Outsourced Support
A dedicated compliance and billing audit partner tracks regulatory changes like the AUC pause as they happen, rather than relying on individual staff members to catch a CMS transmittal buried in routine correspondence. This matters specifically for a program with as unpredictable a history as AUC.
What Ongoing Audits Typically Cover
A regular audit process reviews ordering NPI accuracy across the imaging claim volume, confirms diagnosis codes align with current LCDs, and flags any legacy AUC codes still being submitted unnecessarily. This keeps a practice’s imaging billing workflow current without requiring internal staff to track every regulatory shift themselves.
Conclusion
Medicare AUC compliance in Athenahealth today looks very different from what it looked like just a few years ago. Claims-based AUC reporting is currently paused, and practices no longer need to attach G-codes and modifiers to advanced imaging claims. But the underlying statute remains on the books, and the ordering physician NPI requirement, medical necessity documentation, and standing coverage rules for radiology and cardiology imaging were never tied to AUC in the first place, which means they remain fully active.
FAQs
Do practices still need to report AUC consultation on Medicare imaging claims?
No. As of January 1, 2024, CMS directed providers to stop including AUC consultation information on Medicare fee-for-service claims. The requirement is currently paused, not permanently eliminated.
Could the AUC payment penalty phase still happen in the future?
It’s possible. The underlying statute, PAMA Section 218(b), was never repealed. The payment penalty phase was never implemented, and CMS could reinstate claims-based reporting requirements in a future rule.
Is the ordering physician NPI requirement connected to the AUC program?
No. The ordering or referring provider NPI requirement on imaging claims comes from separate, longstanding Medicare ordering and referring provider edits. It remained in effect even after AUC claims reporting was paused.
Which imaging services were covered under the AUC program?
The program applied to advanced diagnostic imaging services, including MRI, CT scans, nuclear medicine, and PET scans. It never applied to X-rays, ultrasound, or fluoroscopy.
What still causes imaging claim denials if AUC reporting is paused?
Most current imaging denials trace back to standing requirements unrelated to AUC, including missing ordering physician NPIs, diagnosis codes that don’t support medical necessity under the applicable Local Coverage Determination, and mismatched professional/technical component billing.
