Group Practice Speciality Issue

I am billing for Group Practice having physicians with multiple specialities. UHC is duplicating claims of our Reumatalogist with Pulmonologist as both physician seen the patient on the same date. We billed diagnosis according to their specialities but they are still denying due to duplicate. One of CSR asked us to appened a Modifier that shows the difference in speciality. Can someone help me with this. Is there any Modifier that shows difference in Speciality.What I need to do. Please suggest me.

Thanks

re: Group Practice Speciality Issue

There is no modifier for this. What modifier did she want? I have heard of groups using modifier 25. It's not really correct coding--....

Be sure that each specialty is enrolled with the correct specialty code.

Are both physicians using the same diagnosis code? If seeing the patient for the same problem, of course, they will be.