Hi Eldon Barrowes DDS! The diagnosis code(s) will depend on the patient”s condition – basically – what is the reason the service is being done? For example, if the sinus lift is being performed due to atrophy of the maxilla, some coding options are: K08.24 – Minimal atrophy of maxilla K08.25 – Moderate atrophy of the maxilla K08.26 – Severe atrophy of the maxilla If it is being done for a different reason, let me know and I would be happy to offer you some additional coding options. Hope this helps!