Pathology/Lab Coding Alert

Find out if your lab can use modifier 90.

Whether you’re dealing with claims for clinical lab or pathology procedures, knowing how to use certain modifiers can smooth the way to fewer denials and better pay.

Read on for our experts’ advice about modifiers you need to know.

Distinguish ‘Separate Procedures’ With These Modifiers

The National Correct Coding Initiative (NCCI) includes Procedure-to-Procedure (PTP) edit pairs that bundle codes you should not report together under normal circumstances because they represent overlapping services. But sometimes it’s appropriate to report a bundled code pair together, so you need a way to identify those circumstances.

Enter modifiers. Appending the appropriate modifier to the procedure code will alert the payer that the two codes were not part of a single procedure normally performed together. You’ll use a modifier when providers perform bundled procedures at different sessions, at different anatomic sites, or on separate lesions or excisions.

Most specific: Many modifiers can do the job of identifying separate procedures, but you should always use the most specific modifier to describe your case. That means modifier 59 (Distinct procedural service) should be the last modifier of choice.

In place of 59, coders now have the following, more specific modifiers that describe in what way the procedures are distinct:

• XE (Separate encounter, a service that is distinct because it occurred during a separate encounter): Use this for bundled procedures on specimens acquired from separate encounters on the same date of service.
• XS (Separate structure, a service that is distinct because it was performed on a separate organ/structure): Use this for bundled services on specimens taken from distinct anatomic sites or possibly from distinct specimens (such as lesions) from a single anatomic site.
• XP (Separate practitioner, a service that is distinct because it was performed by a different practitioner)
• XU (Unusual non-overlapping service, the use of a service that is distinct because it does not overlap usual components of the main service)

Different anatomic site: For different anatomic sites, you may also turn to specific anatomical modifiers, such as LT (Left side (used to identify procedures performed on the left side of the body)) and RT (Right side (used to identify procedures performed on the right side of the body)). “Anatomical modifiers designate the area or part of the body on which the procedure is performed and assist in prompt, accurate adjudication of claims,” says Mary I. Falbo, MBA, CPC, CEO of Millennium Healthcare Consulting Inc. in Lansdale, Pennsylvania.

For instance: If your pathologist examines a fine needle aspiration specimen from a left breast lesion and an enhanced cyst aspiration smear from the right breast, NCCI edits prohibit billing together 88173 (Cytopathology, evaluation of fine needle aspirate; interpretation and report) and 88112 (Cytopathology, selective cellular enhancement technique with interpretation (eg, liquid based slide preparation method), except cervical or vaginal). But you may override the edit pair by appending appropriate modifiers, such as 88173-LT and 88112-RT. Or you could appropriately report the case as 88173 and 88112-XS. Payers may offer guidance on which modifiers to use in such cases.

Don’t Sink Clinical Lab Claims by Ignoring These Modifiers

Clinical laboratories must operate with a specific certification level under the Clinical Laboratory Improvement Amendments (CLIA). “The provider must be a certificate holder in order to legally perform clinical laboratory testing,” explains Marcella Bucknam, CPC, CCS-P, COC, CCS, CPC-P, CPC-I, CCC, COBGC, revenue cycle analyst with Klickitat Valley Health in Goldendale, Washington.

The most basic certification level is the certificate of waiver, which is a common level for physician office labs. Such labs are approved to perform only “waived” tests, which the Food and Drug Administration (FDA) determines based on simplicity of use and low risk for erroneous results.

QW: When a lab with a certificate of waiver performs a CLIA-waived test, you must append modifier QW (CLIA waived test) to the appropriate code. “CMS publishes a list of waived tests quarterly, and this list indicates which codes must be accompanied by the QW modifier,” Bucknam says.

Note that a few common tests mentioned on the first page of the list, for example, 81002 (Urinalysis, by dip stick or tablet reagent for bilirubin, glucose, hemoglobin, ketones, leukocytes, nitrite, pH, protein, specific gravity, urobilinogen, any number of these constituents; non-automated, without microscopy) and 81025 (Urine pregnancy test, by visual color comparison methods), don’t require modifier QW to be recognized as a waived test. You can link to the latest update for changes effective April 1 at www.cms.gov/files/document/r11188CP.pdf.

91: Sometimes clinicians have medically necessary reasons to order the same test (reported with the same CPT^® code) more than one time on the same date of service. You’ll need to append modifier 91 (Repeat clinical diagnostic laboratory test) to each subsequent repeat test following the first.

Caution: You should use this modifier only when the clinician requests a repeat test on the same date of service “because the physician needs comparative results,” according to Bucknam. You should never use modifier 91 “for a repeat lab procedure due to an inadequate sample, quality control or confirmation results,” she says.

For instance: Clinicians may order a creatine kinase (CK) test for a patient presenting with cardiac symptoms and order repeat tests at six-hour intervals. Increasing CK levels may indicate a myocardial infarction (MI). You should report the initial test as 82550 (Creatine kinase (CK), (CPK); total), and each subsequent test on the same date of service as 82550-91.

90: When a provider bills for a clinical lab test that they didn’t perform but instead sent to an outside lab, they should list the appropriate code with modifier 90 (Reference (Outside) Laboratory). That’s true “when one laboratory references out a test to another laboratory,” Bucknam says. But this modifier comes with lots of baggage, and you need to know whether you can use it, and if so, when and how.

First: Only an independent clinical laboratory (specialty code 69) may bill for a test that it refers to a reference lab. Although physician office labs used to bill for tests that they sent out, that’s no longer allowed. The reference lab must bill for those tests.

Second: Not all independent labs qualify for referred billing (also called third-party billing) when they send out a test. The independent lab must also meet one of the following criteria:

• The referring laboratory is located in, or is part of, a rural hospital.
• The referring laboratory is wholly owned by the entity performing such test, the referring laboratory wholly owns the entity performing such test, or both the referring laboratory and the entity performing such test are wholly owned by a third entity.
• The referring laboratory does not refer more than 30 percent of the clinical laboratory tests for which it receives requests for testing during the year (not counting referrals made under the wholly owned condition described above).

Third: The name, address, and CLIA number of both the referring laboratory and the reference laboratory must be on the claim.

Fourth: Only one lab can bill for the test. If the reference lab is billing, the referring lab should not bill the code. That means modifier 90 will not be involved in the claim.

Unprocessable: Note that if you bill for a referred test and your lab does not qualify for specialty code 69, or if you bill a referred test without modifier 90, Medicare will return the claim as unprocessable.

Source: You can find this modifier 90 guidance in the Medicare Claims Processing Manual, Chapter 16, Section 40.1 (www.cms.gov/Regulations-and-Guidance/Guidance/Transmittals/Downloads/R23CP2.pdf).