Contact-Insurance mapping has been setup in the contacts display so that if a contact is a referring provider, the id of that referring provider can be included on the cms form.
To setup the mapping you need to edit a contact. You will notice the grid at the bottom for the insurance information.

To add a mapping select the Add button.
Select an insurance company in the subsequenct dialog and select the Select button.
Fill in the id information and select the Save button.
To edit a mapping select an insurance company in the "Insurance Information" section and select the Edit button.
Modify the id to the new value and select the Save button.
To remove a mapping select an insurance company in the "Insurance Information" section and select the Remove button.
Select Yes to remove the mapping.