I have several claims that I have been paid for the annual or office visit. The patient then becomes pregnant shortly after and we bill the Global Delivery code. BCBSM will pay for the delivery, then come and take back the payment for Annual or Office visit. (stating it was during the global period of delivery, this is false in most cases we did not know that patient was pregnant at the time of service.) I have called asking how I can get these paid and they are stating I am missing a modifier. Does anyone know what modifier I should be attaching to the corrected claims. I have tried Modifier 24 and 79 and was told that they are both incorrect. Any help would be greatly appreciated.