We are having a lot of discussion on whether it is appropriate for a coder to review past encounters for lab orders for a diagnosis. With our system the encounters do not link when a patient is seen in the clinic and later returns for lab draws, returning testing fluids, etc. Is it appropriate for a coder to search back for the encounter that the labs were ordered in to be able to append a diagnosis for the lab only visit? Is there a guideline for this practice? Any thoughts, suggestions, or concrete eveidence would be greatly appreciated.