It is important to remember that the primary reason for the patient’s visit indicates the primary diagnosis code pointer that should be used on the claim. Diagnosis code pointers are used to indicate the appropriate order of importance in relation to the service being performed. The first pointer designates the primary diagnosis for the service line. Remaining diagnosis pointers indicate declining level of importance to service line.
For additional information about properly completing the form, view the CMS-1500 Instructions on the National Uniform Claim Committee (NUCC) 
website.