Pathology/Lab Coding Alert

CCI limits some -- but not all -- molecular diagnostics

The upside to the latest molecular diagnostics/array edits is not what CCI bundles -- but what it doesn-t.

Leaving molecular diagnostic preparation codes (83890-83892, 83898-83901) out of the equation clarifies that you can report these services in addition to the appropriate array code (88384-88386).

The Correct Coding Initiative (CCI), version 13.2, is effective July 1. You can view the edits on the Internet at www.cms.hhs.gov/NationalCorrectCodiNitEd/01_overview.asp.

The latest CCI edits clarify coding among various code families that describe molecular techniques by introducing 69 new edit pairs involving the following array codes:

CCI pairs each of these codes with each other and with each of the codes from molecular cytogenetics (88271-88275), in situ hybridization (ISH, 88365-88368) and many molecular diagnostics codes (83893-83897 and 83902-83914).

What's similar: All of these tests use nucleic acid probes -- small segments of DNA or RNA flagged with a marker such as a fluorescent dye -- that the lab can use to identify patient protein or genetic material to help characterize disease.

What's different: Arrays, commonly called "gene chips," are devices that can hold many genetic probes in specific positions on a solid surface. "Array technology involves nucleic acid probes or DNA sequences imbedded in a platform such as a slide, chip or microbeads," says Diana Voorhees, MA, CLS, MT(ASCP)SH, CLCP, principal with DV and Associates Inc. in Salt Lake City.

"Microarrays" might pack thousands of probes on a tiny chip, but an array can also be as few as 12 probes fixed on a slide. You-ll recognize when your lab is using an array because it is generally a commercial product that a lab purchases and uses to analyze a given specimen. You-ll just use one code to report the entire analysis and interpretation involving many probes.

For instance: If the pathologist interprets a test that has 44 probes as part of an array device that the lab purchases and uses, you should report 88384 for the test. You should document your code selection by stating that the lab used an array-based evaluation. Although arrays often involve large numbers of probes, the method, not the number of probes, is the key to code selection, Voorhees says.

In contrast: Molecular diagnostics codes describe each step of the process that the lab performs, so you-ll report multiple codes for a single analysis and interpretation. For instance, if the lab analyzes the same 44 specific nucleic acid probes as the preceding example but not using an array, you would individually list each probe using 83896 (Molecular diagnostics; nucleic acid probe, each). In that case, you should report 83896 x 44, plus 83912 (Molecular diagnostics; interpretation and report) for the interpretation.

Whether array or standard molecular diagnostics, both methods involve identifying patterns of gene sequence and/or expression and interpreting these patterns. Physicians use the tests to predict biological behavior of certain cancers, for instance, or to indicate susceptibility to treatment regimes.

Don't miss: CCI adds new edit pairs with 88384-88386 because array codes include the identification and interpretation service that the following molecular diagnostics codes represent:

Watch modifier indicator: Because CCI lists all of these edit pairs with a "1" modifier indicator, you can override the edit pairs in certain circumstances. "If the lab performs a molecular diagnostics study analyzing a set of MD probes and performs a separate array study using unique probes for a distinct evaluation, you can report the codes together," says William Dettwyler, MT-AMT, president of Codus Medicus, a laboratory coding consulting firm in Salem, Ore. You should use modifier 59 (Distinct procedural service) to indicate that you are reporting two separate analyses.

Account for interpretation: Although you need to bill for the pathologist's interpretation of array results, you shouldn't do so by using molecular diagnostics interpretation code 83912, which CCI 13.2 bundles with arrays. "The array codes include the evaluation and reporting services, so you should not list 83912 with 88384-88386," Voorhees says.

Whether the lab uses an array or standard molecular diagnostics techniques to identify and interpret gene expression, the lab has to perform certain steps to obtain the genetic material for analysis. These steps involve extracting the nucleic acids from the specimen (digestion, isolation) and "copying it" (amplification) to produce enough material for testing.

Because these steps are not part of the array service, CCI does not bundle the molecular diagnostics codes for extraction and amplification with array codes 88384-88386.

Opportunity: You can list any of the following codes with an array code if your lab performs the step(s). Don't miss out on the fair payment your lab deserves for this work, as indicated in the table by the Clinical Laboratory Fee Schedule's national limit amount:

CCI doesn't bundle these codes with array codes in accordance with a CPT text note following 88386 that says, "For preparation of array-based evaluation, see 83890-83892, 83898-83901."

When your lab uses an array evaluation of genetic material, you should choose only one code (88384, 88385 or 88386) for the service. Base your selection on the number of probes that the array uses: 11-50, 51-250 or 251-500, respectively.

Pitfall: You should not use these codes together for a single array -- you-re not counting up probes and using 88384 for the first 50, 88385 for the next 200, etc. Instead, you must determine the number of probes in the array and select the single code that lists the range your probe number falls into. That's why CCI added edit pairs for 88384, 88385 and 88386 with each of the other codes in the family.

How you know: "The manufacturer's literature should specify the number of probes, and you can use this information to select 88384, 88385 or 88386," Voorhees says.

Exception: You cannot report an array code for fewer than 11 probes, regardless of the method. A CPT text note following 88386 says, "For preparation and analyses of less than 11 probes, see 83890-83914."