Summary & Overview
HCPCS G1004: Clinical Decision Support Mechanism for Appropriate Use Criteria
HCPCS Level II code G1004 denotes a clinical decision support mechanism provided by a national decision support company under the Medicare Appropriate Use Criteria program. The code captures services that supply evidence-based AUC guidance to clinicians at the point of ordering, supporting appropriate imaging and diagnostic decision-making. National attention to this code reflects broader efforts to standardize and document decision support processes tied to utilization management and quality initiatives.
Key payers discussed include Aetna, Blue Cross Blue Shield, Cigna Health, UnitedHealthcare, and Medicare. Readers will find a concise overview of what the code represents, typical service settings, and the national policy context. The publication also outlines payer coverage considerations, common modifiers associated with billing for related services, and areas where data were not provided.
This summary provides clinicians, billing professionals, and policy staff with practical context: how G1004 maps to a remote clinical decision support service, where it is typically used, and which major payers are relevant for coverage and claims submission. The report highlights benchmarks, regulatory alignment with the Medicare AUC program, and common administrative considerations for claim processing. Data not available in the input are noted explicitly where applicable.
Billing Code Overview
HCPCS Level II code G1004 describes a clinical decision support mechanism provided by a national decision support company, as defined by the Medicare Appropriate Use Criteria program. The service represents the provision of a centralized decision support system that delivers appropriate use criteria (AUC) guidance to clinicians to inform imaging and other diagnostic decisions.
Service type: Clinical decision support service
Typical site of service: This service is delivered remotely and integrated into clinical workflows across settings such as ambulatory clinics, hospital outpatient departments, and inpatient facilities via electronic health record or ordering systems.
Data not available in the input.
Clinical & Coding Specifications
Clinical Context
A primary care physician or ordering clinician uses a certified national clinical decision support (CDS) mechanism to query Appropriate Use Criteria (AUC) at the time of ordering an advanced imaging test (for example CT, MRI, nuclear medicine) for a patient with acute or chronic symptoms. Typical patient scenario: an adult patient presents to outpatient clinic with acute flank pain, suspected renal colic, and hematuria. The clinician enters the imaging order into the electronic health record (EHR), the order triggers a query to the national CDS company using the AUC program, and the CDS returns a guidance response indicating whether the proposed CT abdomen/pelvis without contrast meets AUC. The clinician documents the query response and proceeds with ordering the imaging study when appropriate.
Typical clinical workflow:
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Clinician evaluates patient and determines indication for advanced imaging.
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Clinician places imaging order in the EHR and selects clinical indication.
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EHR sends a standardized query to the national decision support company (
G1004describes the CDS mechanism service). -
CDS returns AUC-based decision support result (e.g., “appropriate,” “may be appropriate,” or “rarely appropriate”) and supporting rationale.
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Clinician documents the CDS response in the patient record, includes any necessary modifier or justification, and finalizes the imaging order.
Typical site of service: outpatient clinic, ambulatory care centers, hospital outpatient department, or integrated health system EHR ordering environment. Common participating payors include Aetna, Blue Cross Blue Shield, Cigna Health, UnitedHealthcare, BUCA, and Medicare.