In CanadianEMR Alan Brookstone writes about the complex complex issues that arrive as we move to the EMR in physician practices. Including retention of paper records and the possiblity that if the Physician changes from one EMR to another EMR they might have to keep both running to meet the requirements under the law.

Part of  the answer is in a Continuity of Care Record not discussed in this thread on CanadianEMR but the there are a number of situations that are worthy of review.  you can find Dr. Brookstone's writings at: http://emruser.typepad.com/canadianemr/2006/08/retention_of_re.html