Pathology/Lab Coding Alert

When you-re billing for molecular diagnostics studies that involve steps to "amplify" genes or fluorescent tags, you need to know about CPT 2008 code changes to keep your claims clean. Follow our experts- advice to update your molecular diagnostics coding savvy so you can pick the right codes.

You-ve had codes for nucleic acid sequence and signal amplification for years, but CPT 2008 revises the definitions for clarity:

"CPT 2008 has removed the reference to patient nucleic acid and substituted the word -target- in codes 83898, 83900 and 83901" says Diana Voorhees, MA, CLS, MT (ASCP) SH, CLCP, principal with DV and Associates Inc. in Salt Lake City.

"Similarly, CPT 2008 eliminates -patient nucleic acid- and changes word order for the 83908 code definition, but the description still indicates and differentiates that this code identifies signal amplification," Voorhees says.

"Taken together, these changes should help clarify differences in lab procedures for amplification of a targeted nucleic acid versus amplification of a signal," she says.

Do this: You should still use these codes the same way you did before the 2008 terminology clarification. Select the appropriate code(s) 83898 or 83900-83901 for target amplification based on whether the lab performs a multiplex reaction. You should still reserve 83908 to report signal amplification if the lab performs that step.

New CPT 2008 text notes confirm this usage:

- a note following 83898 states, For signal amplification, use 83908

- a note following 83908 states, For target amplification, see 83898, 83900, 83901.

CPT 2008 makes other changes to clarify coding for multiplex reactions -- amplifications that involve more than one nucleic acid sequence in a single tube.

Avoid this: Don't use multiple units of 83898 for multiplex reactions. To ensure that you select the more appropriate codes, CPT 2008 adds a text note following 83898 that states, "For multiplex target amplification, see 83900, 83901."

Know unit of service: For the first two nucleic acid sequences in a multiplex reaction, list one unit of 83900. But if the tube contains additional nucleic acid sequences, you should list one unit of 83901 for each.

Don't miss: Because it is an add-on code, you should only use 83901 with 83900 when the multiplex reaction involves more than two nucleic acid sequences. A change to the 83901 code definition for 2008 clarifies this usage.

"The addition of the words -beyond 2- clarifies that 83901 should only accompany the use of CPT 83900," Voorhees says.

For instance: A Tay Sachs disease HEXA gene mutation study involves amplification of five nucleic acid sequences in a single tube. Report the service as 83900 for the first two nucleic acid sequences, plus 83901 x 3 for the remaining nucleic acid sequences amplified.

Molecular diagnostics testing involves many codes beyond those modified in CPT 2008. When your lab performs molecular diagnostics testing, you should use the appropriate combination of codes from the range 83890-83913 to report the service.

"Each code describes a separate technique, such as cell lysis, nucleic acid extraction or mutation identification, and you should report each step using the suitable code," says Elizabeth Sheppard, HT(ASCP), manager, technical marketing for Ventana Medical Systems in Tucson, Ariz.

Charge once for interpretation: Each molecular diagnostics study -- not each individual step in the process -- involves a professional interpretation of the results. Regardless of the number of technical procedure codes (83890-83913) involved in an individual study, you should report the interpretation with a single unit of 83912 (Molecular diagnostics; interpretation and report).

Missed modifier could cost you: Because the Medicare Physician Fee Schedule (MPFS) lists 83912 with modifier 26 (Professional component), a pathologist (or an independent lab billing for the pathologist) should bill 83912-26. That will ensure payment from the MPFS -- $17.52 for national 2008 pricing.

On the other hand, you-ll get paid from the Clinical Laboratory Fee Schedule -- $5.60 for the 2008 national limit amount -- if you list 83912 without the modifier when an independent or hospital lab nonphysician provides the interpretation.

Grasp new CPT terminology: Two steps that your lab might perform as part of a molecular diagnostics study involve amplifying the "target" gene sequence or the fluorescent "signal" to improve test quality. Make sure you understand these and other molecular diagnostics terms with "Know the -Signal- to Keep Your Molecular Diagnostics Coding on -Target- " below.