Q If we discover twins during a transvaginal ultrasound, are we allowed to bill this code twice?
A By adding new codes and revising some old ones, CPT has created a very specific set of instructions about billing for multiple gestations.
In the case of ultrasounds for fetal and maternal evaluation, CPT offers “add-on” codes to be used for each additional fetus (for example, 76802, each additional gestation [list separately in addition to the code for the primary procedure]). For limited ultrasound, we are told to essentially ignore the presence of twins for billing purposes. For follow-up ultrasound, we are instructed to bill for each gestation using modifier-59 (distinct procedure) for each additional fetus examined and documented.
Unfortunately, there are no instructions regarding the transvaginal code. Whether this was an oversight remains to be seen. I recommend erring on the conservative side and billing the transvaginal code only once if the physician is simply noting the number of gestational sacs during the scan.
Remember that although a transvaginal scan is frequently performed to check on specific factors (like fetal viability), it also may be done in conjunction with the abdominal approach to help the physician completely visualize all structures of concern. For a multiple gestation, any detailed documentation of fetal anatomy will usually come from the abdominal, not the transvaginal, scan.