Pathology/Lab Coding Alert

Modifier 59 (Distinct procedural service) frequently tops the list of most misused modifiers, according to the HHS Office Inspector General (OIG) error rate reports over the years.

“Distinct Procedural Service: … Modifier 59 is used to identify procedures/services, other than E/M services, that are not normally reported together, but are appropriate under the circumstances. Documentation must support a different session, different procedure or surgery, different site or organ system, separate incision/excision, separate lesion, or separate injury (or area of injury in extensive injuries) not ordinarily encountered or performed on the same day by the same individual.”

While there are other reasons to use this modifier, “[National Correct Coding Initiative] NCCI edits are the main reason,” explained Cox. “It provides a way for us to be able to report multiple services that are done at the same session on the same date that might be considered bundled by the powers that be,” she continued.

Example: The pathologist examines a small bowl specimen and evaluates multiple qualitative immunohistochemistry (IHC) stains, including one for CD4 and one for CD20. In addition to the microscopic findings, to reach a final diagnosis, the pathologist needs to quantify the two markers and perform flow cytometry for CD4 and CD20 levels. That means the pathologist reports 88342 (Immunohistochemistry or immunocytochemistry, per specimen; initial single antibody stain procedure) and +88341(… each additional single antibody stain procedure (List separately in addition to code for primary procedure)) for the IHC stains, plus 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)) and 88187 (Flow cytometry, interpretation; 2 to 8 markers) for the flow cytometry performed later the same day.

NCCI bundles 88342 as a column 2 code for 88184 and 88187. The NCCI Policy Manual, Chapter 10 states that one of the methods “should establish the diagnosis,” but allows that if “the initial method does not explain all the light microscopic findings… the physician may report both methods using modifier 59 or XU [Unusual non-overlapping service, the use of a service that is distinct because it does not overlap usual components of the main service] and document the need for both methods in the medical record.”

Beware 59’s Bad Reputation

Despite modifier 59’s usefulness, overuse and misuse are prevalent “across all payers, across all specialties,” said Cox.

In fact, in a recent False Claims Act (FCA) case, a Michigan physician faced massive fines and jail time. One of his alleged crimes was the improper use of modifier 59 to boost reimbursement from federal health programs by unbundling services that should not have been billed separately.

Don’t Default to 59

Performing two procedures does not automatically mean you’ll need to append the 59 modifier. A common error is for coders to append modifier 59 for all separate procedures, regardless of whether they’re even bundled. That will lead to a swift denial.

For instance: If the pathologist examines a skin excision and bills 88305 (Level IV - Surgical pathology, gross and microscopic examination, … Skin, other than cyst/tag/debridement/plastic repair …) on the same date as a lymph node resection (88307, Level V - Surgical pathology, gross and microscopic examination … Lymph nodes, regional resection), don’t use modifier 59. Codes 88305 and 88307 are not bundled. That means you can bill the two codes separately without a modifier.

Differentiate 59 from X{EPSU}

Temptation to default to the 59 modifier tends to extend to circumstances when another modifier is better suited for the situation. You should always choose the most specific modifier that is most appropriate for the circumstances.

In an attempt to mitigate the common 59 modifier issues, The Centers for Medicare & Medicaid Services (CMS) created the X{EPSU} modifiers, which allow you to more specifically report a distinct procedure. When you’re tempted to turn to 59 to override an NCCI edict pair, consider looking at the following when billing CMS or payers following Medicare rules:

• XE (Separate encounter …). Use modifier XE for a service that is distinct because it occurred during a separate encounter. Only use this modifier to describe separate encounters on the same date of service.
• XP (Separate practitioner …). Turn to modifier XP for a service that is distinct because a different practitioner performed it.
• XS (Separate structure …). Modifier XS should be your choice for a service that is distinct because it was performed on a separate organ/structaure.
• XU (Unusual non-overlapping service …). Finally, use modifier XU for a service that is distinct because it does not overlap usual components of the main service, such as the above example concerning IHC and flow cytometry.

Expert tip: In relationship to the X{EPSU} modifiers, reporting 59 is similar to reporting a truncated ICD-10-CM code without enough characters. You can think of reporting the X{EPSU} modifiers as “the equivalent of reporting 59 with a higher level of specificity,” said Pam Vanderbilt, CPC, CDEO, CPB, CPMA, CPPM, CPC-I, CEMC, CPFC, CEMA, owner of Knowledge Tree Billing, Inc. during her HEALTHCON presentation “Unbundling Modifiers: A Risky Business.”

Labs: Clinical labs have the same X{EPSU} modifier choices to override NCCI edit pairs. But you face an additional problem when billing multiple units of a single clinical lab test, even if the clinician orders the repeat test on the same date for medical reasons. Although modifier XE may seem like the solution for lab tests taken at separate encounters, you have a more specific modifier you should use in these cases: modifier 91 (Repeat clinical diagnostic laboratory test).

Final caution: Some payers prefer 59 to the X modifiers, and some prefer the X modifiers over the 59. Be sure to check with the payer to avoid denials, Cox warned.