Pathology/Lab Coding Alert

Pick the correct modifier for repeat tests.

You can hardly watch a medical TV show or spend a single day in a clinical lab without facing an order for a complete blood count (CBC). But don’t be fooled into thinking that coding CBCs is easy just because they’re common.

Three major snares stand in the way of correct coding and payment for CBCs, and we’re here to tell you how to dodge the damage and win the day.

Trap 1: The Differential WBC Can Trip You Up

CPT^® provides two codes for CBC — with and without differential white blood cell (WBC) count — so that’s easy enough, right?

Not so fast: Those two codes work for a straightforward CBC order with or without automated differential WBC, as you can see in the descriptors below:

• 85025 (Blood count; complete (CBC), automated (Hgb, Hct, RBC, WBC and platelet count) and automated differ­ential WBC count)
• 85027 (… complete (CBC), automated (Hgb, Hct, RBC, WBC and platelet count))

But if you consider common situations like manual (not automated) differential WBC testing, or reflex testing for abnormal differential WBC findings, coding can get messy.

Glossary: First you need to know the definitions of the following terms:

• WBC: White blood cells, also called leukocytes, are one of the three main blood cell types (WBC, red blood cells, and platelets). WBCs are part of the immune system, defending against infectious agents.
• Differential WBC: Instead of measuring the total WBC count, this procedure measures the level of different types of leukocytes. The main types of WBCs are granulocytes (neutrophils, eosinophils, and basophils), lymphocytes (T cells and B cells), and monocytes.
• Reflex test: A lab test performed automatically following initial (ordered) test results that meet certain defined criteria, such as specific abnormal findings. Labs set up reflex testing for situations involving an original test result that is inconclusive without further testing. Labs typically use the original specimen and do not need to contact the ordering physician to perform the reflex test.

Manual: If a physician orders a CBC with manual differential, you shouldn’t use 85025. Instead, “you should report 85027 plus 85007 (Blood count; blood smear, microscopic examination with manual differential WBC count),” says William Dettwyler, MT-AMT, president of Codus Medicus, a laboratory coding consulting firm in Salem, Oregon.

Reflex: You can report 85027 and 85007 together even if the clinician orders a CBC without a differential and the lab reflexes to a manual differential based on abnormal CBC findings, such as an out-of-range WBC count, according to CPT^® guidance. Recognizing “that some laboratories commonly must perform manual … leukocyte differentials depending on the results of the other CBC parameters,” labs should use 85027 for the CBC without differential, “then code the appropriate additional evaluation necessary … [such as] 85007,” according to CPT^® Assistant, January 2004, Volume 14, Issue 1. The National Correct Coding Initiative (NCCI) does not bundle 85027 and 85007.

Except: If the ordered CBC includes automated differential, you should not separately report a reflex to manual differential. “Even though the lab performs two separate tests in this reflex testing scenario, you should not add a manual diff charge (85007) to the CBC plus automated diff (85025),” Dettwyler says.

Reason: The NCCI Policy Manual for Medicare services, Chapter X..H.2 states that a lab “may not report … 85025 with a manual differential WBC count (CPT^® code 85007) because this combination of codes results in duplicate payment for the differential WBC count.” In fact, NCCI bundles 85025 and 85007 with a modifier indicator of “0,” meaning that you cannot override the edit pair under any circumstances.

Do this: For the reflex scenario where the order is for CBC with automated differential, “report the service as 85025,” Dettwyler says. “Medicare’s stance is that if you must perform the second differential to accomplish what the doctor ordered, that work is part of the original 85025 service.”

Trap 2: Repeat CBCs Need a Reason

Clinicians may order repeat CBC tests on the same day for medically necessary reasons, such as monitoring patient condition or response to treatment. To avoid a denial for the second test, you need to turn to the appropriate modifier.

For an ordered repeat lab service for comparative results, you should use modifier 91 (Repeat clinical diagnostic laboratory test). This modifier indicates that “it is medically necessary to do the lab test more than one time in one day,” says Jennifer Swindle, vice president of quality and service excellence at Salud Revenue Partners in Lafayette, Indiana.

Example: A provider orders a complete blood count (CBC) with automated differential WBC for a patient, which is performed in-house. The results come back in an hour, and later in the day, the physician needs a second reading to confirm improvement or decline. The practitioner orders the test to be retaken, “so you would report 85025 twice, appending modifier 91 on the second CBC along with documentation supporting medical necessity for a second test,” says Kelly C. Loya, CPC-I, CHC, CPhT, CRMA, associate partner, Pinnacle Enterprise Risk Consulting Services LLC in Centennial, Colorado.

Remember: You would use modifier 91 only on the second test, and “only when the results of both labs are needed. If the initial sample is contaminated, or if there is not enough blood or an adequate sample, then it should not be billed as a repeat lab,” Swindle says.

Trap 3: Watch Out for Platelet Pitfall

Both codes 85025 and 85027 list the following CBC components: hemoglobin (Hgb), hematocrit (Hct), red blood cell count (RBC), WBC count, and platelet count.

Rule: If you use a lab code that describes a panel of individual tests (as 85025 and 85027 do), you should not report the panel code if any individual test component is missing.