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    v1.0.28
    OpenPayerBilling CodesAdministrative, Miscellaneous and InvestigationalHCPCS hcpcs-a9558-xenon-ventilation-gas-diagnostic
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    HCPCS Level II A9558: Xenon Xe-133 Gas, Diagnostic, per 10 Millicuries

    HCPCS Level II code A9558 describes diagnostic xenon Xe-133 gas supplied in units of 10 millicuries for nuclear medicine ventilation studies; the service is supply of a radiopharmaceutical agent used in pulmonary ventilation imaging and the typical site of service is an outpatient imaging center or hospital radiology/nuclear medicine department.

    For related coverage guidance, see recent payer policy updates: Interferential Stimulation Devices (for home use), Durable Medical Equipment (DME): Tumor Treating Fields (Alternating Electric Field Therapy) Medical Guideline, Durable Medical Equipment (DME): Bone Growth Stimulators Medical Guideline.

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    Clinical & Coding Specifications

    Clinical Context

    A typical patient is an adult referred to nuclear medicine for a quantitative ventilation study using xenon-133 gas to evaluate regional pulmonary ventilation in the setting of suspected pulmonary embolism, chronic obstructive pulmonary disease, or preoperative pulmonary function assessment prior to lung resection. The patient arrives to the outpatient nuclear medicine suite or hospital imaging department. A technologist confirms identity, indications, allergies, and pregnancy status. The patient is positioned supine on the gamma camera; a closed-circuit breathing apparatus or rebreathing system is placed to administer Xenon Xe-133 gas. Serial ventilation images are acquired while the patient breathes the tracer per protocol. Images are reviewed by the nuclear medicine physician for ventilation distribution, wash-in/wash-out dynamics, and correlation with any concurrently obtained perfusion images. The report documents the administered activity in millicuries (per A9558 units per 10 millicuries), imaging technique, findings, and interpretation. Typical sites of service include the hospital nuclear medicine department, outpatient imaging center, or freestanding ambulatory imaging facility.

    Related CPT Codes

    CPT CodeDescriptionRelationship to This Procedure
    78801Lung perfusion study, quantitative, planar with or without SPECTTypically performed alongside a ventilation study to form a V/Q comparison for pulmonary embolism evaluation
    71045Radiologic examination, chest; single view, frontalMay be performed prior to nuclear study as part of chest imaging workup
    93970Duplex scan of extremity veins including all venous imaging of the deep venous system; noninvasive evaluation for venous thromboembolismOften performed in conjunction with V/Q studies when clinical suspicion for thromboembolism exists
    0340TQuantitative single photon emission CT (SPECT) of the lungs, ventilation and perfusionAdvanced or SPECT-based ventilation-perfusion studies that may accompany or replace planar xenon techniques
    88360Immunohistochemistry or special stain; per specimenNot directly related to imaging; Data not available in the input.

    Related Modifiers

    9 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…
    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…
    78CPT modifier -78 indicates an unplanned, related return to the operating or procedure room by the same provider during the global postoperative period. It is appended when treatment for a…- Use modifier -78 when an unplanned, related complication during the original procedure’s global postoperative period requires the patient to return to a formal operating or procedure room and the…
    80CPT® Modifier 80 (Assistant Surgeon) is appended to a surgical CPT code when a physician (MD or DO) provides full, continuous assistance throughout the operative procedure. It is intended only for…- Use CPT Modifier -80 when a physician (MD or DO) serves as an assistant surgeon and provides full, continuous assistance throughout the entire operative procedure; append -80 to the surgical CPT…
    82Modifier 82 is appended to a surgical CPT code to indicate that an attending physician acted as an assistant because a qualified resident surgeon was unavailable. In teaching hospitals it documents…- When to use: Append modifier 82 in teaching-hospital settings to indicate a physician served as an assistant surgeon because a qualified resident surgeon was unavailable (includes situations where…
    26Modifier 26 (Professional Component) identifies and bills only the professional portion of a split service — the physician’s interpretation, report, and medical judgment — when the technical…- Use CPT Modifier -26 when you are billing only the professional component (PC) of a split‑bill eligible service—i.e., you performed the physician interpretation, medical judgment and prepared a…

    Related Provider Taxonomies

    8 rows

    Taxonomy CodeSpecialtyNotes
    208000000XPediatrics PhysicianA pediatrician is concerned with the physical, emotional and social health of children from birth to young adulthood. Care encompasses a broad spectru…
    207P00000XEmergency Medicine PhysicianAn emergency physician focuses on the immediate decision making and action necessary to prevent death or any further disability both in the pre-hospit…
    2084P0800XPsychiatry PhysicianA Psychiatrist specializes in the prevention, diagnosis, and treatment of mental disorders, emotional disorders, psychotic disorders, mood disorders, …
    207L00000XAnesthesiology PhysicianAn anesthesiologist is trained to provide pain relief and maintenance, or restoration, of a stable condition during and immediately following an opera…
    207WX0009XGlaucoma Specialist (Ophthalmology) PhysicianAn ophthalmologist who specializes in the treatment of glaucoma and other disorders related to increased intraocular pressure and optic nerve damage. …
    124Q00000XDental HygienistAn individual who has completed an accredited dental hygiene education program, and an individual who has been licensed by a state board of dental exa…
    246RM2200XMedical Laboratory TechnicianTechnologists, Technicians & Other Technical Service Providers · Technician, Pathology
    174V00000XClinical EthicistA clinical ethicist has been trained in bioethics and ethics case consultation. The clinical ethicist addresses medical-ethical dilemmas arising in c…

    Related ICD-10-CM Codes

    22 rows

    ICD-10-CM CodeDescription
    C34.11Malignant neoplasm of upper lobe, right bronchus or lung
    C34.90Malignant neoplasm of unspecified part of unspecified bronchus or lung
    C34.91Malignant neoplasm of unspecified part of right bronchus or lung
    C78.00Secondary malignant neoplasm of unspecified lung
    C78.01Secondary malignant neoplasm of right lung
    I26.99Other pulmonary embolism without acute cor pulmonale
    I27.9Pulmonary heart disease, unspecified
    J44.9Chronic obstructive pulmonary disease, unspecified
    J45.909Unspecified asthma, uncomplicated
    J96.00Acute respiratory failure, unspecified whether with hypoxia or hypercapnia

    Showing 1–10 of 22

    Related Payer Policy Updates

    Specialty: Durable Medical Equipment (DME)1 / 3

    5 rows

    PolicyPayerEffective Date
    Interferential Stimulation Devices (for home use)Moda Health2026-10-01
    Durable Medical Equipment (DME): Tumor Treating Fields (Alternating Electric Field Therapy) Medical GuidelineWPS Health Insurance2026-10-01
    Durable Medical Equipment (DME): Bone Growth Stimulators Medical GuidelineWPS Health Insurance2026-10-01
    General Durable Medical Equipment (DME) Medical GuidelineWPS Health Insurance2026-10-01
    Prior Authorization for Durable Medical Equipment (DME)Blue Cross Blue Shield - Rhode Island2026-10-01

    Related Codes

    HCPCS-A9150-NON-PRESCRIPTION-DRUGS

    HCPCS Level II A9150: Non-prescription Drugs

    HCPCS-A9152-SINGLE-ORAL-VITAMIN-MINERAL-DOSE

    HCPCS A9152: Single Oral Vitamin/Mineral/Trace Element

    HCPCS-A9153-MULTIVITAMIN-ORAL-PER-DOSE

    HCPCS A9153: Multiple Vitamins, Oral, Per Dose

    HCPCS-A9154-ARTIFICIAL-SALIVA-1ML

    HCPCS Level II A9154: Artificial saliva, 1 ml

    HCPCS-A9155-ARTIFICIAL-SALIVA-30ML

    HCPCS Level II A9155: Artificial Saliva, 30 mL

    HCPCS-A9156-ORAL-MUCOADHESIVE-PER-1ML

    HCPCS Level II A9156: Oral Mucoadhesive, Per 1 ml

    HCPCS-A9180-PEDICULOSIS-TOPICAL-TREATMENT-PATIENT-ADMINISTRATION

    HCPCS Level II A9180: Pediculosis Topical Treatment for Patient/Caretaker

    HCPCS-A9268-PROGRAMMER-TRANSIENT-INGESTED-CAPSULE

    HCPCS Level II A9268: Programmer for Transient Orally Ingested Capsule

    HCPCS-A9269-PROGRAMMABLE-TRANSIENT-ORAL-CAPSULE

    HCPCS Level II A9269: Programmable Orally Ingested Capsule, Per Month

    HCPCS-A9270-NON-COVERED-ITEM-OR-SERVICE

    HCPCS A9270: Non-covered Item or Service

    Showing 1–10 of 138

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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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