Pathology/Lab Coding Alert

Question: How should we code for fetal aneuploidy (trisomy 21, 18, and 13, which we already report as 81507, and sex chromosome aneuploidy from a single specimen?

South Carolina Subscriber

Answer: There are different kinds of tests for sex chromosome aneuploidy, so the coding would depend on the method.

The person states that they’re coding 81507 (Fetal aneuploidy (trisomy 21, 18, and 13) DNA sequence analysis of selected regions using maternal plasma, algorithm reported as a risk score for each trisomy) for the trisomy panel. Assuming that you’re just adding the sex chromosome aneuploidy (SCA) to the genetic panel performed on maternal plasma (cell-free fetal DNA) for a single test that is a larger panel, the correct code would be 81420 (Fetal chromosomal aneuploidy (eg, trisomy 21, monosomy X) genomic sequence analysis panel, circulating cell-free fetal DNA in maternal blood, must include analysis of chromosomes 13, 18, and 21). You should report 81420 instead of 81507 and an additional code.

A known test by Natera (the Panorama NIPT test) uses maternal blood for a genetic panel for trisomy 21, 18, 13 plus SCAs monosomy X, XXY syndrome, XYY syndrome, and triple X syndrome – labs bill that test as 81420, and that seems to be what the questioner is doing.