If you have been searching by the name of the practice or doctor, make sure you have spelled it correctly. The search may find similar names, but it does not find names that are shortened. E.g. the search for the term “Mei” will not find any doctors with the name “Meier”.
It may be that the doctor’s specialty is not stored. Try a search without specialty if you had this field set and didn’t find the desired doctor.
The more open a search is, the more doctors will be found. But only a certain amount of doctors can be displayed. If you have reached this limit and didn’t find your doctor, try to refine your search criteria.