Ob-Gyn Coding Alert

Question: I was hoping I could get some guidance on the new Z36 codes that just went in effect on October 1st. We do ultrasounds on patients that we already know the last menstrual period (LMP), but we are checking dates. So can we use Z36.87, because we are just making sure, or should we use Z36.89 instead? We aren't doing it because the LMP is uncertain. We also do a routine 32 week growth (fundal height=gestational age). What should we use for this?

Minnesota Subscriber

Answer: You should only report code Z36.87 (Encounter for antenatal screening for uncertain dates) when this information is not known or in doubt. You could, in fact, know the LMP, but the physician may think it may not be right so does the screening.

If this is your routine scan on all patients as an antenatal test, you would instead report Z36.89 (Encounter for other specified antenatal screening). The routine fundal growth scan should also be coded using a Z36.89 if there is no medical indication for doing so.

For instance, if the uterine size and dates did not match you would instead report O26.84- (Uterine size-date discrepancy complicating pregnancy).

Heads up: The American Congress of Obstetricians and Gynecologists (ACOG) has made it very clear that all ultrasounds beyond performing the initial anatomy scans and nuchal translucency scans would need medical justification. You would only report Z36.89 if this was antenatal screening for a reason that was not spelled out in the other Z36 codes.