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Apurva Posted Wed 01st of July, 2020 07:21:08 AM
The guidelines on when FISH can be order (how many times per year)?
SuperCoder Answered Thu 02nd of July, 2020 06:13:31 AM


Thank you for your Question!


As per CMS, There are two sets of codes that describe in situ hybridization (ISH). Although the laboratory methods are similar, one distinguishes between the two sets of codes based on whether the ISH test is an adjunct to a surgical or cytopathology case, versus whether it is part of the clinical, chromosomal analysis.


Specifically, the CPT codes 88271-88291 should be used when the laboratory performs ISH as an ancillary analysis to cytogenetic studies for oncologic or inherited disorders. This test ordered by physicians because a FISH test can detect genetic abnormalities associated with cancer, it's useful for diagnosing some types of the disease. When the type of cancer has previously been diagnosed, a FISH test also may provide additional information to help predict a patient's outcome and whether he or she is likely to respond to chemotherapy drugs.


When a pathologist performs ISH techniques (ISH is a lab method that uses a nucleic acid (DNA or RNA) sequence (called a “probe”) that carries a label such as a fluorescent dye) as an adjunct to a surgical pathology or cytopathology case, CPT codes 88365-88377 should be used to distinguish qualitative versus quantitative analysis (computer-assisted versus manual). These codes must never be used by a pathologist when ISH is performed as an ancillary analysis of cytogenetic studies.


CPT® ISH code families and some unique FISH codes by first identifying the clinical context. Please find the undermentioned categorized FISh service-related codes for better understanding.


  • Histopathology/cytopathology: “Pathologists may evaluate tissue or cytology specimens using an ancillary ISH service, often as part of cancer diagnosis,” e.g (88365-88366), 88120, 0009U & 0053U. These codes used in addition to surgical pathology codes 88302-88309 (Level … Surgical pathology, gross and microscopic examination …) or cytopathology codes such as 88172-88173 and +88177 (Cytopathology, evaluation of fine needle aspirate …) or 88104-88112 (Cytopathology…) for tissue or cytology specimens. The tests normally aid in the diagnosis and characterization of cancers.


  • Molecular cytogenetics: If you’re coding for a clinical lab test as an ISH test for a cytogenetics case, not a histopathology or cytopathology case, you should turn to a different set of codes, as follows:

           88271 (Molecular cytogenetics; DNA probe, each (eg, FISH))

           88272 (… chromosomal in situ hybridization, analyze 3-5 cells (eg, for derivatives and markers))

           88273 (… chromosomal in situ hybridization, analyze 10-30 cells (eg, for microdeletions))

           88274 (… interphase in situ hybridization, analyze 25-99 cells)

          88275 (… interphase in situ hybridization, analyze 100-300 cells)

          88291 (Cytogenetics and molecular cytogenetics, interpretation, and report).


The specimen for these tests may be blood or amniotic or other fluid or maybe a tissue or cell culture. “Clinicians may order these tests to evaluate certain chromosomal or genetic abnormalities, often as part of a larger cytogenetic study, possibly involving other codes in the range 88230-88299,”.


  • Qualitative/ Quantitative: These codes (88365-88377) First divide down along the lines of whether the test is a qualitative “stain” procedure (codes +88364-88366), or a quantitative/semiquantitative evaluation (codes 88367-88377). Within 88367-88377, further subdivision according to analyses that use computer assisted technology (88367, +88373, 88374), or manual quantification methods (88368, +88369, 88377).



Unit of serviceAlthough there are three code families (the qualitative family, the quantitative/manual family, and the quantitative/computer-assisted family), they are similar in reporting the unit of service. Each code family begins with a parent code for the first, single probe procedure. In addition to these codes for the “initial single probe,” each code family also has an indented, add-on code to report additional single probes. Finally, each code family has a code for a “multiplex probe stain procedure.” Use a single unit of these codes if the ISH test identifies multiple antibodies or probes in a single procedure.

Molecular cytogenetics codes for cellular ISH are “building block” codes. You should select the appropriate hybridization code (88272-88275) based on the number of cells analyzed and whether the lab used metaphase or interphase hybridization. In addition to the hybridization, a single ISH study might involve multiple DNA probes, and you should report one unit of 88271 for each probe.

Professional Interpretation Billing Guideline: Use Modifiers TC/26 With Global Codes.

Codes +88364-88377 and 88120-88121 are global codes. That means when you report the code without a modifier, you’re claiming the work of both the technical service, such as preparing the slides and the professional (physician) service, such as interpreting and reporting on the test. The Medicare Physician Fee Schedule (MPFS) lists a payment amount for the global code, plus a sub-divided payment amount when you report the code with modifier TC (Technical component) or 26 (Professional component). “In other words, the global codes inherently involve professional interpretation by the pathologist as an adjunct to the histopathology or cytopathology case,”.

Use Different Strategy for Clinical Tests

  • When you report codes from the 88271-88275 family, you’re not representing any physician professional work. Medicare pays for these codes on the Clinical Laboratory Fee Schedule (CLFS) not the MPFS.
  • Although these codes don’t inherently involve a professional interpretation, a pathologist may need to interpret the test results, in some cases. You should report that professional service as 88291 (Cytogenetics and molecular cytogenetics, interpretation and report) for interpretation of the entire cytogenetics study, possibly including multiple probes and cell counts.


Medicare alert: CMS assigns 88291 a Medically Unlikely Edit (MUE ) of 1 and considers the code to represent the interpretation and report of “all cytogenetic/molecular cytogenetic testing performed on a single date of service,” according to the NCCI Policy Manual.

Kindly refer undermentioned links for more detailed information on FISH.


Hope that Helps!

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