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    v1.0.28
    OpenPayerBilling CodesProcedures / Professional ServicesHCPCS hcpcs-g1003-clinical-decision-support-appropriate-use
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    HCPCS G1003: Clinical Decision Support Mechanism (Medicalis)

    HCPCS Level II code G1003 represents billing for a clinical decision support mechanism (Medicalis) as defined by the Medicare Appropriate Use Criteria program, used to provide automated, evidence-based imaging appropriateness guidance at the point of electronic order-entry; service type is clinical decision support software/service and the typical site of service is ambulatory/outpatient or hospital electronic order-entry environments.

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    Table of contents

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    • Billing CodesCPT, HCPCS, DRG & more
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    Clinical & Coding Specifications

    Clinical Context

    A 62-year-old male with a history of stable coronary artery disease presents to a hospital-based radiology department for evaluation of new-onset exertional chest pain. The ordering cardiologist requests a coronary computed tomography angiography (CCTA) and, per Medicare Appropriate Use Criteria (AUC) program policy, the facility uses a certified Clinical Decision Support Mechanism (CDSM) — billed with G1003 — to document that the imaging order aligns with AUC. The clinical workflow: the ordering clinician enters the imaging order into the electronic health record (EHR) with the patient’s history and provisional diagnosis; the EHR triggers the integrated CDSM which prompts selection of the relevant clinical scenario and provides an appropriateness score. The clinician documents the CDSM response in the order and proceeds with scheduling. At the time of service the imaging center documents the CDSM transaction, links it to the imaging study, and includes G1003 on the claim to indicate use of a certified clinical decision support mechanism as defined by the Medicare Appropriate Use Criteria program.

    Related CPT Codes

    CPT CodeDescriptionRelationship to This Procedure
    71260CT thorax; with contrast material(s)May be the imaging study ordered for chest pain after CDSM review and documented with G1003
    75574Computed tomographic, heart, coronary artery(s) with contrast, including image post-processing when performedCommonly ordered for suspected coronary disease; CDSM documents appropriateness prior to performing this study
    72125CT thoracic spine without contrastMay be ordered for thoracic pain etiologies where CDSM assists appropriateness determination
    93298Comprehensive electrophysiologic evaluation including device interrogation and programming (noninvasive)May be performed in parallel for cardiac symptom evaluation when imaging order was reviewed by the CDSM
    93000Electrocardiogram, routine ECG with at least 12 leads; with interpretation and reportCommonly performed before cardiac imaging; CDSM use does not alter ancillary ECG coding but is part of the overall diagnostic workflow

    Related Modifiers

    8 rows

    ModifierDescriptionWhen to Use
    22Modifier –22 (Increased Procedural Services) is used when a reported procedure is substantially more extensive than normally required. The CPT Manual and CMS state it may be appended only when the…- When to use: Append modifier -22 to a procedural CPT code when the service performed is substantially more extensive than the usual service described by that code — i.e., the procedure required…
    23Modifier -23 (Unusual Anesthesia) is used on anesthesia service CPT codes when a procedure that normally requires no anesthesia or only local anesthesia must be performed under general anesthesia…- Use modifier -23 only on anesthesia CPT codes (00100–01999) when a procedure that normally requires no anesthesia or only local anesthesia must be performed under general anesthesia because of…
    52Modifier ‑52 (Reduced Services) indicates that a service or procedure was partially reduced or omitted at the provider’s discretion, allowing reporting of the basic procedure number with a qualifier…- Use modifier -52 when a physician or qualified health professional electively reduces or omits part of a procedure or service (for example, performing fewer required views or omitting a portion of…
    53Modifier 53 (Discontinued Procedure) signals that a surgical or diagnostic service was begun by the physician but terminated because of extenuating circumstances that threatened the patient’s…- Use modifier -53 when a physician/qualified healthcare professional has started a surgical or diagnostic procedure (e.g., anesthesia administered, incision or scope insertion) and then discontinues…
    54Modifier ‑54 (“Surgical care only”) is appended to a CPT surgical procedure when the reporting surgeon performs the intraoperative (surgical) component but does not furnish the preoperative and/or…- Use modifier -54 when the reporting surgeon provided only the intraoperative (surgical) component of a procedure and preoperative and/or postoperative management has been or will be provided by…
    55Modifier –55 indicates the billing provider furnished only postoperative management for a procedure that has a global surgical period. According to AAPC, this modifier is appended to the same CPT…- Use modifier -55 when billing the same CPT surgical code that has a 10- or 90-day global period and you, as a provider other than the original surgeon, furnished ONLY postoperative management (no…
    56Modifier ‑56 indicates the reporting provider furnished only the preoperative management for a surgical procedure and did not perform the intraoperative or postoperative care. It is used in…- Use Modifier -56 when a provider performs only the preoperative management in a split‑care situation (one physician manages preop care while a different physician performs the intraoperative…
    62Modifier 62 indicates that two surgeons function as co‑surgeons, each performing distinct parts of the same primary surgical procedure. It is appended to the primary procedure code (and any…- Use modifier -62 when two surgeons act as co‑surgeons (both primary surgeons) on a single definitive primary procedure, each performing distinct parts of the same surgical procedure (append -62 to…

    Related Provider Taxonomies

    8 rows

    Taxonomy CodeSpecialtyNotes
    207RC0000XCardiovascular Disease PhysicianAn internist who specializes in diseases of the heart and blood vessels and manages complex cardiac conditions such as heart attacks and life-threaten…
    207RH0000XHematology (Internal Medicine) PhysicianAn internist with additional training who specializes in diseases of the blood, spleen and lymph. This specialist treats conditions such as anemia, cl…
    207L00000XAnesthesiology PhysicianAn anesthesiologist is trained to provide pain relief and maintenance, or restoration, of a stable condition during and immediately following an opera…
    2084P0800XPsychiatry PhysicianA Psychiatrist specializes in the prevention, diagnosis, and treatment of mental disorders, emotional disorders, psychotic disorders, mood disorders, …
    363LF0000XFamily Nurse PractitionerPhysician Assistants & Advanced Practice Nursing Providers · Nurse Practitioner
    246Z00000XOther Specialist/TechnologistGeneral classification identifying individuals trained on specific equipment and technical procedures in one of a collection of miscellaneous healthca…
    171WV0202XVehicle Modifications ContractorA contractor who makes modifications to private vehicles to accommodate a health condition.
    177F00000XLodging ProviderA public or privately owned facility providing overnight lodging to individuals traveling long distances or receiving prolonged outpatient medical ser…

    Related Codes

    HCPCS-G9490-HOME-ASSESSMENT-NON-HOMEBOUND

    HCPCS G9490: Home Visit Patient Assessment for Non-Homebound Beneficiary

    HCPCS-G0008-INFLUENZA-VACCINE-ADMINISTRATION

    HCPCS G0008: Administration of Influenza Virus Vaccine

    HCPCS-G0009-PNEUMOCOCCAL-VACCINE-ADMINISTRATION

    HCPCS G0009: Administration of Pneumococcal Vaccine

    HCPCS-G0010-HEPATITIS-B-VACCINE-ADMINISTRATION

    HCPCS G0010: Administration of Hepatitis B Vaccine

    HCPCS-G0011-PREP-COUNSELING-HIV-RISK-REDUCTION-ADHERENCE

    HCPCS G0011: Individual PrEP Counseling, HIV Risk Assessment

    HCPCS-G0012-PRE-EXPOSURE-PROPHYLAXIS-INJECTION-HIV-PREVENTION

    HCPCS G0012: Injection of PrEP Drug for HIV Prevention

    HCPCS-G0013-PREP-INDIVIDUAL-COUNSELING-HIV-RISK-REDUCTION

    HCPCS G0013: Individual PrEP Counseling by Clinical Staff

    HCPCS-G0017-PSYCHOTHERAPY-CRISIS-FIRST-60-MINUTES-NON-OFFICE

    HCPCS G0017: Psychotherapy for Crisis, First 60 Minutes

    HCPCS-G0018-PSYCHOTHERAPY-CRISIS-ADDITIONAL-30-MINUTES-NON-OFFICE

    HCPCS G0018: Psychotherapy for Crisis, Additional 30 Minutes

    HCPCS-G0019-COMMUNITY-HEALTH-INTEGRATION-SDOH-CARE-COORDINATION

    HCPCS G0019: Community Health Integration, Person-Centered Assessment

    Showing 1–10 of 1996

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    Frequently Asked Questions

    References

    1. 1.CPT® Codes and Descriptions. AAPC. Retrieved Aug 11, 2026.Maintains the CPT code set's official descriptions and guidelines, licensed from the American Medical Association, used as the definitional source for CPT codes on this page.
    2. 2.HCPCS Quarterly Update. Centers for Medicare & Medicaid Services (CMS). Retrieved Aug 11, 2026.CMS's quarterly release of HCPCS Level II codes and short/long descriptors, the source for HCPCS code definitions and update history.
    3. 3.ICD-10-CM Full Code List. Centers for Medicare & Medicaid Services (CMS). Retrieved Aug 11, 2026.CMS's complete ICD-10-CM diagnosis code list, used to cross-reference diagnosis codes associated with this procedure or service.
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