Pathology/Lab Coding Alert

Take this modifier 59 check-up, too.

Selecting just one code from 88187-88189 for your pathologist's flow cytometry panel interpretation has always been correct coding. Now Medicare's Correct Coding Initiative (CCI) gets in on the act to enforce that rule.

Pathologists use the flow cytometry codes (88184-88189) for immunophenotyping of hematolymphoid cancers -- often as an adjunct test for surgical pathology specimens. The flow cytometry testing involves panels of "markers" that require interpretation by the pathologist. For the technical work involved in performing the test panel, report the following codes:

- 88184 -- Flow cytometry, cell surface, cytoplasmic, or nuclear marker, technical component only; first marker

- +88185 -- each additional marker (List separately in addition to code for first marker).

In addition to always reporting 88184, you should list multiple units of 88185 based on the number of markers beyond the first marker in the panel.

Interpretation is separate: Based on the number of markers in the panel, you should choose only one of the following codes to describe the pathologist's interpretation:

- 88187 -- Flow cytometry, interpretation; 2 to 8 markers

- 88188 -- 9 to 15 markers

- 88189 -- 16 or more markers.

These codes are not additive. For example, you should not list 88187 for the first eight markers, plus 88188 for markers number nine through 15. "You should select one code to describe the interpretation of all flow cytometry markers for a single specimen," says Peggy Slagle, CPC, billing compliance coordinator at the University of Nebraska Medical Center in Omaha.

For instance: If the panel has nine markers or 13 markers, you should select 88188 for the interpretation. If the panel has 18 markers, select 88189.

Watch for edit pairs: CCI version 14.3, effective Oct. 1, bundles 88187 as a component of 88188 and 88189, and also bundles 88188 as a component of 88189. That means you can't report any of the codes together, but should instead select the most comprehensive code that describes the number of markers in the single panel. If you bill two of these codes, CMS will deny the lesser code anyway.

If you can document that your pathologist performed two bundled procedures and how medical necessity for the service, you might be able to override the CCI edit pair.

Here's how: According to CMS instruction, you should append modifier 59 (Distinct procedural service) to "the secondary, additional, or lesser procedure(s) or service(s)" to indicate that you performed two separate procedures. But even with proper documentation, you can't always use modifier 59.

Here's why: The CCI edit table has a "modifier indicator" column. If the codes you-re trying to report together have an indicator of "1" next to them, you may be able to append modifier 59 to bypass the edit. If the code has a "0" indicator, you cannot bypass the edit under any circumstances. The CCI edits change quarterly, so be sure to keep abreast of all updates.

For example: The new edit pairs for flow cytometry interpretation have a "1" modifier indicator. That means you can override the edit pairs in the rare case that the pathologist performs two separate interpretations -- that is, if the pathologist interprets two separate flow cytometry panels.

Some coders have heard rumors that CCI is instituting a claim edit that would allow payment only for specific code pairs with modifier 59, based on recommendations from the Office of Inspector General (OIG).

Although the OIG found a 40-percent error rate on claims that contained modifier 59 and encouraged carriers to institute a claims edit that would allow payment only for specific code pairs reported with the modifier, CMS has not implemented such an edit.

"It would be very tough for a carrier to make that type of edit stick," says Kurt Clawson, biller with CGH Billing in Louisville, Ky. "There are just way too many claims that include modifier 59, and that type of edit would slow things down almost to a screeching halt."