Pathology/Lab Coding Alert

Question: Our lab performs high resolution HLA Class I typing, sometimes testing for one locus (A, B, or C), or any combination of two loci, or all three loci. I know I’m reporting the correct code, because we’re getting paid for one or two loci. But my claims get denied when I report three units of the code for three loci — why is that?

Codify Subscriber

Answer: Presumably you are reporting the test as 81380 (HLA Class I typing, high resolution [i.e., alleles or allele groups]; one locus [e.g., HLA-A, -B, or -C], each). That is the correct code if you’re billing human leukocyte antigen (HLA) Class I typing for HLA-A, or HLA-B, or HLA-C, or any two of these types.

However, the fact that you’re getting denials for billing three units of 81380 is not surprising.

Here’s why: CPT^® provides a separate code that describes testing for all three HLA Class I loci typing. That code is 81379 (HLA Class I typing, high resolution [i.e., alleles or allele groups]; complete [i.e., HLA-A, -B, and -C]).

To make sure you abide by this rule, CPT^® has a text note under 81380 directing you to code 81379 for complete Class 1 typing. Also, the Centers for Medicare and Medicaid Services (CMS) has instituted and medically unlikely edit (MUE) limit of two for code 81380.