Let me try this:
Every procedure in the book has as a natural component the evaluation necessary to follow the procedure through to completion. If the E&M is significant; meaning beyond what is needed for the procedure,but still applicable to the patient's presenting issue(s),; and separately identifiable; meaning are the key elements of the E&M able to be separated from that which is needed for the procedure and still have a viable level; then you meet the criteria for the 25 modifier. You do not need a separate dx code only the criteria for the 25.