Are the oral disclosure requirements under 226.26 applicable to a consumer's inquiry on an existing loan?

I'm not sure what you are asking.

If I call in to see what the current interest rate is on my loan then no you would not have to quote the APR. You already did that with the TIL you gave me.

However, if I call in to see what my the current interest is and then inquire what the rate would be if I refinanced then you would have to quote the APR for the refinancing rate, whether it would be the same rate or a different rate.