CPT 85004: Automated White Blood Cell Differential

CPT code 85004 describes an automated white blood cell differential in which a lab analyst reviews a blood smear on a slide and uses an automated system to count and classify the different types of white blood cells; service type: hematology/laboratory diagnostic test; typical site of service: clinical laboratory or hospital laboratory.

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CPT 85004: Automated White Blood Cell Differential

Customize your policy alerts

Sign up for cpt 85004 policy alerts

Get alerted when payer policies referencing 85004 are released or updated.

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Receive email alerts as soon as relevant payer policies are published or updated.

Clinical & Coding Specifications

Clinical Context

A typical patient is a adult or pediatric outpatient presenting to a primary care clinic, urgent care, emergency department, or hospital inpatient unit with symptoms such as fever, malaise, cough, or suspected infection. The clinician orders a complete blood count with differential; a phlebotomist draws a blood specimen which is routed to the laboratory. In the lab, a technologist or lab analyst prepares a slide or loads the sample into an automated hematology analyzer that performs a white blood cell differential, enumerating neutrophils, lymphocytes, monocytes, eosinophils, and basophils. Results are reviewed by the lab, validated, and reported to the ordering clinician to aid in diagnosis and management of infection, inflammation, hematologic disorders, medication effects, or monitoring of therapy (for example, chemotherapy or immunosuppression). Typical sites of service include outpatient clinics, urgent care centers, hospital laboratories, and reference laboratories. Workflow steps: order entry by clinician, specimen collection, specimen accessioning, analysis (manual review or automated differential), result validation, and result reporting into the medical record or lab information system.

Related CPT Codes

CPT Code	Description	Relationship to This Procedure
`80053`	Comprehensive metabolic panel; blood chemistry profile	Often ordered alongside a CBC with differential to assess electrolyte and organ function during acute illness
`80061`	Lipid panel	May be ordered in outpatient preventive or metabolic evaluations performed during the same visit
`81002`	Urinalysis, non-automated, without microscopy	Frequently performed in the workup of infection or systemic illness alongside CBC with differential
`85014`	Blood count; automated differential WBC count	Related automated differential code; `85004` describes the lab analyst analyzing on a slide with automated system — `85014` is the automated differential often billed in similar workflows
`36415`	Collection of venous blood by venipuncture	The specimen collection procedure performed prior to laboratory analysis
`86353`	C-reactive protein; quantitative	An inflammatory marker commonly ordered together with differential to assess acute inflammation

Related Modifiers

6 rows

Modifier	Description	When to Use
26	Modifier 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…
90	Modifier ‑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…
59	Modifier 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…
52	Modifier ‑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…
53	Modifier 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…
63	Modifier‑63 is appended to surgical CPT codes (20000–69990) when a procedure is performed on a neonate or infant weighing ≤ 4 kg (about 8.8 lbs). The AMA/AAPC definition specifies this use and notes…	- Use modifier -63 only for surgical procedures in the CPT 20000–69990 series performed on a neonate or infant who weighs ≤ 4 kg at the time of the procedure; it indicates increased complexity due to…

Related Provider Taxonomies

8 rows

Taxonomy Code	Specialty	Notes
208D00000X	General Practice Physician	A physician who specializes in the general practice of diagnosing, treating, and managing patients with a variety of illnesses and conditions.
207R00000X	Internal Medicine Physician	A physician who provides long-term, comprehensive care in the office and the hospital, managing both common and complex illness of adolescents, adults…
207Q00000X	Family Medicine Physician	Family Medicine is the medical specialty which is concerned with the total health care of the individual and the family. It is the specialty in breadt…
207P00000X	Emergency Medicine Physician	An emergency physician focuses on the immediate decision making and action necessary to prevent death or any further disability both in the pre-hospit…
207L00000X	Anesthesiology Physician	An anesthesiologist is trained to provide pain relief and maintenance, or restoration, of a stable condition during and immediately following an opera…
156FX1900X	Orthoptist	An orthoptist is an allied health professional skilled in evaluation and treatment of children and adults with eye movement difficulties. Their specia…
2084P0802X	Addiction Psychiatry Physician	Addiction Psychiatry is a subspecialty of psychiatry that focuses on evaluation and treatment of individuals with alcohol, drug, or other substance-re…
364SM0705X	Medical-Surgical Clinical Nurse Specialist	Physician Assistants & Advanced Practice Nursing Providers · Clinical Nurse Specialist

Related Codes

CPT-85002-BLEEDING-TIME-TEST-LABORATORY

CPT 85002: Bleeding Time Test, Technical Component

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

CPT-85032-MANUAL-DIFFERENTIAL-BLOOD-SMEAR-COUNT

CPT 85032: Manual Differential/Visual Cell Count

Showing 1–10 of 99

Frequently Asked Questions

References

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.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.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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Clinical & Coding Specifications

Clinical Context

Related CPT Codes

CPT Code	Description	Relationship to This Procedure
`80053`	Comprehensive metabolic panel; blood chemistry profile	Often ordered alongside a CBC with differential to assess electrolyte and organ function during acute illness
`80061`	Lipid panel	May be ordered in outpatient preventive or metabolic evaluations performed during the same visit
`81002`	Urinalysis, non-automated, without microscopy	Frequently performed in the workup of infection or systemic illness alongside CBC with differential
`85014`	Blood count; automated differential WBC count	Related automated differential code; `85004` describes the lab analyst analyzing on a slide with automated system — `85014` is the automated differential often billed in similar workflows
`36415`	Collection of venous blood by venipuncture	The specimen collection procedure performed prior to laboratory analysis
`86353`	C-reactive protein; quantitative	An inflammatory marker commonly ordered together with differential to assess acute inflammation

Related Modifiers

6 rows

Modifier	Description	When to Use
26	Modifier 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…
90	Modifier ‑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…
59	Modifier 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…
52	Modifier ‑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…
53	Modifier 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…
63	Modifier‑63 is appended to surgical CPT codes (20000–69990) when a procedure is performed on a neonate or infant weighing ≤ 4 kg (about 8.8 lbs). The AMA/AAPC definition specifies this use and notes…	- Use modifier -63 only for surgical procedures in the CPT 20000–69990 series performed on a neonate or infant who weighs ≤ 4 kg at the time of the procedure; it indicates increased complexity due to…

Related Provider Taxonomies

8 rows

Taxonomy Code	Specialty	Notes
208D00000X	General Practice Physician	A physician who specializes in the general practice of diagnosing, treating, and managing patients with a variety of illnesses and conditions.
207R00000X	Internal Medicine Physician	A physician who provides long-term, comprehensive care in the office and the hospital, managing both common and complex illness of adolescents, adults…
207Q00000X	Family Medicine Physician	Family Medicine is the medical specialty which is concerned with the total health care of the individual and the family. It is the specialty in breadt…
207P00000X	Emergency Medicine Physician	An emergency physician focuses on the immediate decision making and action necessary to prevent death or any further disability both in the pre-hospit…
207L00000X	Anesthesiology Physician	An anesthesiologist is trained to provide pain relief and maintenance, or restoration, of a stable condition during and immediately following an opera…
156FX1900X	Orthoptist	An orthoptist is an allied health professional skilled in evaluation and treatment of children and adults with eye movement difficulties. Their specia…
2084P0802X	Addiction Psychiatry Physician	Addiction Psychiatry is a subspecialty of psychiatry that focuses on evaluation and treatment of individuals with alcohol, drug, or other substance-re…
364SM0705X	Medical-Surgical Clinical Nurse Specialist	Physician Assistants & Advanced Practice Nursing Providers · Clinical Nurse Specialist

Related Codes

CPT-85002-BLEEDING-TIME-TEST-LABORATORY

CPT 85002: Bleeding Time Test, Technical Component

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

CPT-85032-MANUAL-DIFFERENTIAL-BLOOD-SMEAR-COUNT

CPT 85032: Manual Differential/Visual Cell Count

Showing 1–10 of 99

Frequently Asked Questions

References

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.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.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.

Published by

Trek Health powers OpenPayer with a leading commercial payer intelligence platform, seamlessly converting fragmented payer data into actionable insights for provider organizations.

CPT 85004: Automated White Blood Cell Differential

Sign up for cpt 85004 policy alerts

CPT 85004: Automated White Blood Cell Differential

Sign up for cpt 85004 policy alerts

Clinical & Coding Specifications

Clinical Context

Related CPT Codes

Related Modifiers

Related Provider Taxonomies

Related Codes

What does CPT 85004 represent?

In what clinical settings is 85004 commonly performed?

Which related tests are often ordered alongside CPT 85004?

For which diagnoses is an automated WBC differential (85004) clinically relevant?

What are the typical laboratory workflow steps associated with the 85004 procedure?

References

Clinical & Coding Specifications

Clinical Context

Related CPT Codes

Related Modifiers

Related Provider Taxonomies

Related Codes

What does CPT 85004 represent?

In what clinical settings is 85004 commonly performed?

Which related tests are often ordered alongside CPT 85004?

For which diagnoses is an automated WBC differential (85004) clinically relevant?

What are the typical laboratory workflow steps associated with the 85004 procedure?

References