Just a little confuse on when to use these numbers. In p.36 of the chapter on how to fill up Box 24I, it says "Enter the alpha numeric qualifier for the non NPI provider identifier number that.... ". Does that mean that we will always use the Qualifier Number which is 1B in this example and the "NPI" text is always there? What do you mean by non NPI provider I.D when in fact, it has already the NPI? Also, what is the difference between a Rendering Provider ID vs. NPI vs. Billing Physician ID#?