Pathology/Lab Coding Alert

Question:  Our lab performs testing for genetic carrier status for cystic fibrosis in both the prospective mother and father. How should we code the test, both procedure and diagnosis codes?

Kentucky Subscriber

Answer: The appropriate diagnosis codes for procreative genetic disease carrier status are as follows:

• Z31.430 (Encounter of female for testing for genetic disease carrier status for procreative management)
• Z31.440 (Encounter of male for testing for genetic disease carrier status for procreative management).

You should assign the procedure code based on the lab test performed. The most common test for cystic fibrosis (CF) genetic carrier status is 81220 (CFTR (cystic fibrosis transmembrane conductance regulator) (eg, cystic fibrosis) gene analysis; common variants (eg, ACMG/ACOG guidelines)).

You would need to bill the test code once for each prospective parent. The code represents testing for the most common changes to the cystic fibrosis transmembrane conductance regulator (CFTR) gene that are associated with a risk of passing cystic fibrosis to a child. Because the test evaluates only the most common genetic CTFR mutations, a negative test result does not necessarily indicate that the male or female tested is not a CF carrier due to a different mutation.