If you are a US citizen or lawful permanent resident you will only need to provide the required proofs on the first, original, amendment, reciprocity or renewal application on or after June 18, 2015.  The proof will be retained on your driving record.
What topic will I find more information on if I go to the MyDMV website?
When the "do it online" button shows in the megamenu, this information is all under the topic "Commercial Drivers".