E/M Servuce

“My documentation for qualified, routine foot care is similar for most patients as little changes in 3 months. But, yes, I do look for changes and make the note reflect such. And I try to make sure notes are not exact copies of previous notes. My notes have plenty of bullet points for an E/M code on each visit. I am primarily charging procedure codes only (CPT 11056, CPT 11721, etc). Can I still bill at least one E/M code per year even when there are no substantive changes as I continually monitor vascular, neurologic and dermal changes each visit? Must I have a new or different diagnosis to bill an E/M code?”