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    v1.0.28
    OpenPayerBilling CodesHematology and Coagulation ProceduresCPT cpt-85379-d-dimer-plasma-assay
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    CPT 85379: D-dimer Assay on Plasma

    CPT code 85379 describes a laboratory assay performed on patient plasma to measure D‑dimer levels, a coagulation/fibrinolysis test used to detect fibrin degradation products; the service is a clinical laboratory diagnostic test typically provided in a hospital laboratory, outpatient laboratory, or independent reference lab setting.

    For related coverage guidance, see recent payer policy updates: Epithelial Cell Cytology in Breast Cancer Risk Assessment, Chemotherapy Observation or Inpatient Hospitalization (for New Mexico Only), Umbilical Cord Blood Harvesting and Storage for Future Use (for Indiana Only).

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    Clinical & Coding Specifications

    Clinical Context

    A typical patient is an adult presenting to an emergency department or outpatient clinic with acute onset unilateral leg swelling, chest pain, shortness of breath, or unexplained tachycardia. The treating clinician orders a plasma D‑dimer test to help evaluate for suspected venous thromboembolism (deep vein thrombosis or pulmonary embolism) or to assist in excluding thrombotic disease in low‑to‑moderate pretest probability patients. Blood is drawn into appropriate anticoagulated tubes, transported to the clinical laboratory, and processed by a laboratory technologist or automated analyzer using CPT 85379 to measure D‑dimer concentration. Results are reported to the ordering clinician to support decisions about imaging (for example, compression venous ultrasound or CT pulmonary angiography) or anticoagulation management. Typical sites of service include the hospital clinical laboratory, outpatient laboratory, and emergency department. The typical specimen is patient plasma obtained from venipuncture and tested by a qualified laboratory analyst or technologist under standard laboratory protocols.

    Related CPT Codes

    CPT CodeDescriptionRelationship to This Procedure
    36415Collection of venous blood by venipunctureBlood draw required to obtain plasma specimen for the CPT 85379 D‑dimer assay.
    71260CT angiography, chest, for pulmonary embolus protocolImaging often performed after an elevated D‑dimer to confirm pulmonary embolism.
    93970Duplex scan of extremity veins (non‑vascular clinical) complete bilateral studyUltrasound used to evaluate suspected deep vein thrombosis when D‑dimer is positive or clinical probability is moderate/high.
    85610Prothrombin time; not otherwise specifiedCommon coagulation test performed alongside D‑dimer in patients with suspected thrombotic or bleeding disorders.
    85730Thrombin timeAdditional coagulation testing sometimes ordered in complex hemostasis evaluations following abnormal D‑dimer results.

    Related Modifiers

    6 rows

    ModifierDescriptionWhen to Use
    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…
    59Modifier 59 indicates a distinct procedural service when two procedures that are not normally billed together are clinically and procedurally separate. The CPT definition (as reiterated by CMS)…- Use modifier -59 to report a distinct procedural service when documentation supports that the procedure reported is not normally billed together with another service on the same day because of a…
    91Modifier 91 — “Repeat Clinical Diagnostic Laboratory Test” — is appended when the exact same CPT laboratory test is performed more than once for the same patient on the same day because serial,…- Use modifier 91 when the exact same CPT laboratory test is performed more than once on the same patient on the same date because serial or repeated testing is medically necessary to monitor…
    90Modifier ‑90 (Reference/Outside Laboratory) indicates that a laboratory test was performed by an entity other than the treating or reporting provider. The American Medical Association defines…- Use CPT modifier -90 when a laboratory test is performed by an outside/reference laboratory (an entity other than the treating or reporting physician or qualified professional) and the claim needs…
    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…

    Related Provider Taxonomies

    8 rows

    Taxonomy CodeSpecialtyNotes
    207R00000XInternal Medicine PhysicianA physician who provides long-term, comprehensive care in the office and the hospital, managing both common and complex illness of adolescents, adults…
    363L00000XNurse Practitioner(1) A registered nurse provider with a graduate degree in nursing prepared for advanced practice involving independent and interdependent decision mak…
    207L00000XAnesthesiology PhysicianAn anesthesiologist is trained to provide pain relief and maintenance, or restoration, of a stable condition during and immediately following an opera…
    208D00000XGeneral Practice PhysicianA physician who specializes in the general practice of diagnosing, treating, and managing patients with a variety of illnesses and conditions.
    207K00000XAllergy & Immunology PhysicianAn allergist-immunologist is trained in evaluation, physical and laboratory diagnosis, and management of disorders involving the immune system. Select…
    1835P2201XAmbulatory Care PharmacistA licensed pharmacist who has demonstrated specialized knowledge and skill in the provision of integrated, accessible health care services by pharmaci…
    171M00000XCase Manager/Care CoordinatorA person who provides case management services and assists an individual in gaining access to needed medical, social, educational, and/or other servic…
    111NN1001XNutrition ChiropractorChiropractic Nutrition is that specialty within the chiropractic profession that deals with the overall factors that affect the patient's ability to m…

    Related Payer Policy Updates

    Specialty: Hematology/Oncology1 / 3

    10 rows

    PolicyPayerEffective Date
    Epithelial Cell Cytology in Breast Cancer Risk AssessmentOscar Health2026-10-01
    Chemotherapy Observation or Inpatient Hospitalization (for New Mexico Only)UnitedHealthcare2026-08-01
    Umbilical Cord Blood Harvesting and Storage for Future Use (for Indiana Only)UnitedHealthcare2026-08-01
    Antibody-Drug ConjugatesPremera Bluecross2026-08-01
    Chimeric Antigen Receptor (CAR) T-Cell TherapyColorado Rocky Mountain Health Plans2026-08-01
    Allogeneic Hematopoietic Progenitor Cell TherapyAmbetter Georgia2026-08-01
    Umbilical Cord Blood Harvesting and Storage for Future Use (for Idaho Only)UnitedHealthcare2026-08-01
    Umbilical Cord Blood Harvesting and Storage for Future Use (for New Jersey Only)UnitedHealthcare2026-08-01
    Umbilical Cord Blood Harvesting and Storage for Future Use (for Ohio Only)UnitedHealthcare2026-08-01
    Reblozyl (luspatercept-aamt) Medical Benefit Drug PolicyUnitedHealthcare2026-08-01

    Related Codes

    CPT-85002-BLEEDING-TIME-TEST-LABORATORY

    CPT 85002: Bleeding Time Test, Technical Component

    CPT-85004-AUTOMATED-DIFFERENTIAL-WHITE-BLOOD-CELL-COUNT

    CPT 85004: Automated White Blood Cell Differential

    CPT-85007-MANUAL-DIFFERENTIAL-WHITE-BLOOD-CELL-COUNT

    CPT 85007: Manual Differential White Blood Cell Count

    CPT-85008-BLOOD-SMEAR-MORPHOLOGIC-REVIEW-NO-DIFFERENTIAL

    CPT 85008: Microscopic Blood Smear Examination, No Differential

    CPT-85009-MANUAL-WBC-COUNT-BUFFY-COAT

    CPT 85009: Manual White Blood Cell Count Using Buffy Coat

    CPT-85013-MICROHEMATOCRIT-TEST-LABORATORY-DIAGNOSTIC

    CPT 85013: Microhematocrit Test by Tube Centrifugation

    CPT-85014-HEMATOCRIT-VOLUME-PERCENT-RED-BLOOD-CELLS

    CPT 85014: Hematocrit (Volume Percent of Red Blood Cells)

    CPT-85018-HEMOGLOBIN-ASSAY-WHOLE-BLOOD

    CPT 85018: Hemoglobin Measurement in Whole Blood

    CPT-85025-COMPLETE-BLOOD-COUNT-CBC

    CPT 85025: Complete Blood Count (CBC)

    CPT-85027-COMPLETE-BLOOD-COUNT-HGB-HCT

    CPT 85027: Complete Blood Count with Hemoglobin and Hematocrit

    Showing 1–10 of 99

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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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