Question: In preparing for the new ICD-10 codes, I have been asked for clarification on the antenatal screening codes. Presently for "Antenatal Screening Labs," we have been using Z36. We call this our routine prenatal labs/profile, which include the following labs: HBsAg screen, Rubella Antibodies, ABO grouping, Rh factor, antibody screen, T pallidum Antibodies, Antibody screen, Hemoglobin, Hematocrit, platelets, UA CBC, chlamydia. GC amplification, HIV. Can we use Z36.89 for this panel or is there a more appropriate code to be used? What would you recommend for gestational diabetes screening in the 3rd trimester? Kentucky Subscriber Answer: For gestational diabetes screening you would be using Z36.89 (Encounter for unspecified antenatal screening) with a secondary code of Z13.1 (Encounter for screening for diabetes mellitus) to fully explain the testing. In fact, Z36.89 will be the most correct code for the tests you have mentioned.