7 Jun 2019

Pathology Coding Guidelines

Pathology Coding Guidelines:

Organ or Disease-Oriented panels

The tests listed with each panel identify the defined components of that panel.

        Any additional tests that are not a component of the specific panel are performed - Report those tests additionally along with the panel code. 

        If a group of tests overlaps two or more panels, report the panel code that incorporates the greater numbers of tests and report the remaining tests using individual test codes.

Drug Assay A test to determine the components of a substance (The presence of a substance and the amount of the substance)

Drug procedures are divided into three subsections:

           1.  Therapeutic drug assay

           2.  Drug assay

           3.  Chemistry

Code selection depended on the purpose and type of patient results obtained.

The 2 major categories for Drug testing in the Drug assay subsection are

          1.  Presumptive Drug Class

          2.  Definitive Drug Class

Presumptive Drug ClassProcedures are used to identify possible use or non-use of a drug or drug class

-      Presumptive Drug Class test may be followed by a definitive test in order to specifically identify the drugs.

Definitive Drug ClassProcedures are Qualitative or A quantitative test to identify possible use or non-use of a drug.

-      These tests identify specific drugs and associated metabolites

-      A presumptive drug test is not required prior to a definitive drug test.

    A.  The materials for the drug class procedures may be any specimen type unless otherwise specified in the code description (Eg: Urine, Blood, oral fluid, meconium, and hair)

    B.  Procedure maybe

1.  Qualitative (Eg. Positive/negative or present/absent)

2.  Semi-quantitative or

3.  Quantitative (measured) depending on the purpose of the testing.

Presumptive screening method

           1.  Immunoassays
           2.  Enzymatic
           3.  Chromatographic method without mass spectrometry (Or) Mass spectrometry without adequate drug resolution by chromatography

        All drug class immunoassays are considered presumptive

Methods that cannot distinguish between structural isomers are also considered as presumptive.

Definitive Drug identification methodable to identify individual drugs and distinguish between structural isomers but not necessarily stereoisomer’s.

        1.  Gas chromatography with mass spectrometry and

        2.  Liquid chromatography with mass spectrometry

Note: For Chromatography – Each combination of stationary and the mobile phase is to be considered as one.

Presumptive Drug class screening 

Drug or class of drug maybe assayed first by Presumptive screening method followed by a definitive drug identification method.

Each code includes a sample validation procedure performed.

  CPT 80305 - Results can be read by the naked eye.
               (Dipsticks, Cups, Cards and cartridges)

  CPT 80306 - Results can be ready by Instrument.
               (Dipsticks, Cups, Cards and cartridges inserted into the instrument)

  CPT 80307 - Instrumented chemistry analyzers.

Note: Report CPT 80305, 80306, 80307 once, irrespective of the number of drug class procedures or results on any date of service. 

Definitive Drug Testing (80320 - 80377)


        1.  Qualitative,

        2.  Quantitative or

        3.  A combination of qualitative and quantitative for the same patient on the same date of service.

Definitive drug class listing TableProvides drug class and associated CPT codes and the drugs included.

        Each category of a drug class including metabolite(s) if performed (Except stereoisomers) is reported once per date of service.

        Metabolites not listed in the table may be reported using the code for the parent drug.

        Drug class may contain one or more codes based on the number of analytes.

For Eg: An analysis in which five or more amphetamines and/or amphetamine metabolites – CPT 80326

Definitive drug procedures that are not listed in CPT 80320 – 80373 should be reported using the unlisted definitive procedure codes (80375, 80376, and 80377) unless specific analyte is listed in the Therapeutic Drug Assays (80150 -80203) or Chemistry (82009 - 84830)

How to code?

Eg # 1: Amphetamine and methamphetamine, any number of definitive procedures – 80324 once per date of service.

Eg # 2: Codeine, hydrocodone, hydromorphone, morphine, any number of definitive procedures – 80361 once per date of service.

Eg# 3: Codeine, hydrocodone, hydromorphone, morphine, oxycodone, oxymorphone, naloxone, naltrexone, any number of definitive procedures – 80361 x1, 80362 x1, and 80365 x1 once per date of service.

Eg# 4: Benzoylecgonine, cocaine, carboxy-THC, meperidine, normeperidine, any number of definitive procedures – 80349 x 1, 80353 x 1, 80362 x 1 per facility per day.

Therapeutic drug assay are performed to monitor clinical response to a known, prescribed medications.

        Therapeutic drug assay (TDA) procedures are typically quantitative tests and the specimen type is whole blood, serum, plasma or cerebrospinal fluid.

        If the same the procedure is performed on more than one specimen type (Eg, Blood and urine) the appropriate code is reported separately for each specimen type and append modifier 59.

        Drugs or classes of drugs may be commonly assayed first by a presumptive screening method followed by definitive drug identification method.

Evocative / Suppression Testing

        The panels involve the administration of evocative or suppressive agents and the baseline and subsequent measurement of their effects on chemical constituents.

        These codes are to be used for the reporting of the laboratory component of the overall testing protocol.

        In the code descriptor the reference is made to a particular analyte (Eg: Cortisol – 82533 x 2) the x 2 refers to the number of times the test for that particular analyte is performed.

Consultations (Clinical Pathology)

        A clinical pathology consultation is a service, including a written report, rendered by the pathologist in response to a request from a physician requiring additional medical interpretive Judgment.

        If there is no medical interpretive judgment in the test results, then it Is not considered a clinical pathology consultation.

Molecular pathology – Tier 1

        Molecular pathology procedures are medical laboratory procedures involving the analyses of nucleic acid (DNA, RNA) to detect variants in genes that may be indicative of

·        Germline (Eg: Constitutional disorders) or

·        Somatic (Eg: neoplasia) conditions, or to test for

·        Histocompatibility antigens (Eg: HLA)

Code selection is based on a specific gene(s) that is being analyzed.

  If only the interpretation and report are performed – append modifier 26 to the molecular pathology code.

  Molecular pathology procedures that are not specified in 81161, 81200 – 81383 should be reported using either the appropriate Tier 2 code (81400 – 81408) (or) the unlisted molecular pathology procedure code (81479)

Molecular Pathology – Tier 2 (81400 - 81479)

ü Tier 2 codes are used -  To report procedures not listed in Tier 1 (81161, 81200 - 81383)

ü Tier 2 procedures are generally performed in lower volume than Tier 1.

ü Codes are arranged by level of technical resources and interpretive work by the physician.

The individual analyses listed under each code utilize the definitions and coding principals as described in the introduction preceding the Tier 1 codes.

ü Use the appropriate level code that includes the specific analyte listed after the code descriptor.

ü If the analyte tested is not listed under Tier 2 codes (or) not represented by a Tier 1 code – Use Unlisted (81479)

Genomic Sequencing Procedures (GSPs)

ü CPT Codes range from 81410 - 81471

ü DNA / RNA sequence analysis methods that simultaneously assay multiple genes relevant to clinical situations.

ü The technology used for Genomic sequencing is referred to as NGS (Next generation sequencing) or MPS (massively parallel sequencing)

ü The GSPs are performed on nucleic acids from germline or neoplastic samples.

ü If the genes that are listed in more than one code descriptor – Report the most specific test for the primary disorder rather than reporting multiple codes for the same genes.

ü If all the components of the descriptor are not performed – Use Tier 1 or Tier 2 codes or Unlisted (81479).


  The materials for examination may be from any source unless otherwise specified in the code descriptor.

If an analyte is measured in multiple specimens from

           1. Different source

           2. A specimen that obtained at different times,

It should be reported separately for each source and for each specimen.


  CPT codes 86602 – 86804 are qualitative or semiquantitative immunoassays performed by multiple-step methods for the detection of antibodies to infectious agents. 

  For immunoassays performed by single-step methods (Eg: reagent strips) use code 86318.

  If multiple tests are performed to detect antibodies to organisms classified more precisely than the specificity allowed by available codes. – Code each as separate service.

  For Example: Enterovirus (86658)
                     Coxsackie - There are no codes for individual species, if assays are performed for antibodies to Coxsackie A and B species – each assay should be coded separately.

  If multiple assays are performed for antibodies of different immunoglobulin classes, each assay should be coded separately.   

            If a coding option exists for reporting IgM specific antibodies (86632) the corresponding nonspecific code (86631) may be reported for the performance of either an antibody analysis not specific for a particular immunoglobulin class or for an IgG analysis. 


  Presumptive identification of microorganism is identification by colony morphology, growth on selective media, Gram stains, or up to three tests (Eg: catalase, oxidase, indole, urease)

  Definitive identification of microorganism is an identification to the genus or species level that requires additional tests (Eg: biochemical panels, slide cultures)

  If additional studies involve molecular probes, nucleic acid sequencing, chromatography, or immunologic techniques – code using 87140 - 87158 in addition to definitive identification codes.

  The molecular pathology codes (81161, 81200 - 81408) are not to be used in combination with or instead of the procedures represented by 87140 - 87158

  Multiple specimen/sites – Use Modifier 59

  Repeat laboratory tests on the same day – Use Modifier 91

Surgical Pathology

  Services 88300 through 88309 include accession, examination and reporting.

  The above codes not include the services designated in codes 88311 – 88365 and 88399 (code in addition if performed)

  The unit of service for codes 88300 – 88309 is the specimen.

  A specimen is defined as tissue that is submitted for individual examination and pathologic diagnosis.

  Two or more specimens from the same patient (Separate lesions) are each appropriately assigned an individual code reflective of its proper level of services.

  CPT 88300 – used for any specimen examining without a microscope.

  CPT 88302 – If a gross and microscopic examination is performed on a specimen to confirm identification and the absence of disease.

  CPT 88304 – 88309 – Gross, microscopic examination and additional ascending levels of physician work.

  Any unlisted specimen should be assigned to the code which most closely reflects the physician work involved.  

Proprietary Laboratory Analyses (PLA) 

Tests with PLA codes must be performed on human specimens and must be requested by the clinical laboratory or the manufacturer that offers the test.