Labs and Pathology Billing Codes

Pathology and laboratory diagnostics CPT codes are used to represent services that involve the evaluation of specimens (e.g., blood, bodily fluid, or tissue) acquired from patients in order to provide information to the treating physician.

Lab services: Involved procedures and services that are performed to evaluate tissues, fluids, and materials.

Pathology services: Involved studying the nature and cause of disease.

Test performed to determine the cause of a patient condition:

Blood test

Drug test



A variety of other assessments

Drug testing (80320- 80377)

Qualitative or screening test: used for monitoring individuals who are suspected of abusing substances. Qualitative tests are used to assess the presence or absence of a substance.

Labs and Pathology Billing Codes

These codes are also used for emergency toxicology assays when evaluating patients suspected of ingesting or being exposed to unknown substances.

When the presence of a drug is detected in the qualitative test, a confirmation test is usually performed by using a second testing method.

Therapeutic Drug Assay (80145- 80377)

Therapeutic drug assay measures the serum level of a drug to ensure its concentration is within the therapeutic range.

The concept of ‘’peak and trough’’ is used during therapeutic drug assay.

Peak levels: check that the drug level is not in the toxic range.

Trough levels: Ensure that the proper medication concentration is maintained.

Quantitative: information determines the presence of a drug and also the exact amount present

CPT and HCPCS Code Modifiers

Modifiers for CPT and HCPCS codes are two-digit codes that are appended to the five-digit CPT code. Modifiers are used to explain unique situations or to provide more information about electrophoresis methods. CMS (rather than the AMA) develops HCPCS Code Modifiers to identify conditions not covered by the CPT.

59 Distinct Procedural Service:

This CPT code modifier is used to indicate a test or service that, despite having the same CPT code, is a unique and distinct test or operation.

Example: Apolipoprotein A and B1 levels are tested concurrently with service. Both assays are reported using the same CPT code (82172, Apolipoprotein, each). To avoid a denial of service, the second code should be reported with the –59 modifier. Payment would be made using the numbers 82172 for Apolipoprotein A and 82172-59 for Apolipoprotein B1.

26 Professional Component: When a physician component of a test (such as interpretation) is recorded separately, this CPT code modification is used to identify it.

90 Reference (Outside) Laboratory: This CPT code modifier is used exclusively by hospital or reference laboratories to indicate tests that are transmitted to other laboratories.

GA Advanced Beneficiary Notice (ABN) on File: This HCPCS code modification is used to indicate that the physician has informed a Medicare patient that the test they are about to undergo may not be covered by Medicare and may be billed to the patient. ABNs must be obtained and signed by the physician and the patient if the patient is to be invoiced for tests or other non-Medicare-covered services.

CPT Codes Associated with Electrophoretic Procedures

Protein Electrophoresis:

84165 Protein fractionation and quantitation by electrophoresis, serum

84166 Protein fractionation and quantification by electrophoresis, other fluids with concentration (eg, urine, CSF) 83916 Immune oligoclonal (oligoclonal bands)

84181 Western blot analysis of a protein with interpretation and report

Each 84182 protein was analyzed using a Western blot and an immunological probe for band identification.

Total Protein Determinations:

84155 Protein total, excluding refractometric

84160 Refractometric total protein

Immunofixation Assays

86334 Serum immunofixation electrophoresis

86335 Immunofixation electrophoresis, other concentrated fluids The CPT code 86334 is assigned to any specimen that does not require concentration.

86335 is used to concentrate any samples (including serum).

Hemoglobin Assays

83020 Electrophoresis for separation and quantification of hemoglobin

83036 A1c glycosylated hemoglobin

Isoenzyme Assays

82552 CK isoenzymes

83625 LDH isoenzymes, separation, and quantitation

84080 Alkaline phosphatase isoenzymes

Lipoprotein Assays

83715 Lipoprotein, blood, electrophoretic separation and quantitation

83716 Lipoprotein, blood, high-resolution fractionation, and quantitation of lipoprotein cholesterols (eg, electrophoresis, nuclear magnetic resonance, ultracentrifugation)

83718 Lipoprotein, direct measurement, HDL cholesterol

83719 Lipoprotein, direct measurement, VLDL cholesterol

83721 Lipoprotein, direct measurement, LDL cholesterol

82172 Apolipoprotein, each

Specimen Collection Codes

Medicare and the majority of other payers permit a separate specimen collection charge for specimens drawn or collected via venipuncture or catheterization, regardless of whether the material is processed on-site or sent to another laboratory for examination. There is a limit of one collection fee per patient interaction, even if numerous specimens are collected.

The following CPT codes are used to document routine blood collection.

36415 Venipuncture collection of venous blood

36416 Capillary blood specimen collection (eg, finger, heel, ear stick)

Routine venipunctures are reported using CPT code 36415. (and for Medicare only, the collection of urine by catheter) Medicare covers HCPCS code 36415 at a flat fee of $3.00 and does not cover CPT capillary blood collection (CPT code 36416).