The Reason Code Library field on the Modify Payer Information window enables you to create and attach a library with reason codes that are unique to a specific payer.
In File Maintenance, select Master Files, then System, and then Payers.
The Payers List window opens.
Double-click the desired payer or right-click open menu , and select Open.
Select the Practice tab and, then Transactions subtab.
Select the desired Reason Code Library for the payer, and then select OK.