I bill to Medicaid for NST's often and occasionally for twins. As of Jan. 1, 2013, we have -been billing:
59025-26(twin A) and 59025-26-59 (twin b). This would be for a single NST performed on that date of service.
If there are two NST's performed on the same date of service, we use:
59025-26 (twin A - am NST), 59025-26-59 (twin b - am NST), 59025-26-76 (twin a - pm NST), and 59025-26-59-76 (twin b - pm NST). This is assuming the same dr. performed all services. If a different provider performed the 2nd NST of the day, you would use -77 modifier instead of -76.
We still have to ask for reconsiderations from time to time, but this seems to be accepted readily. Hope that helps.
Sheri K