One other point. If the patient was diagnosed with a problem by another provider and they switched medical practices and doctors, those problems diagnosed by the prior doctor are "new" to the new provider. They would have to confirm that the prior diagnosis and treatment are correct by discussing things with the patient and evaluating test results etc. An example might be something like a patient who has been diagnosed and treated by doctor A but decides to change to Doctor B for some reason. That's a new patient with a new diagnosis, at least for Doctor B, who would now determine if the patient's treatment is working properly and perhaps even change treatment. Maybe the patient wasn't happy with treatment by Doctor A due to medication or disease side effects the patient didn't feel were being addressed properly, so they decided to change to Doctor B. IMHO Doctor B should be able to get MDM credit for both dealing with the, to them, "new" diagnosis and its subsequent treatment.
Tom Cheezum, OD, CPC, COPC