Final answer:
Under Medicare Part D, both original and electronic Rx records must be preserved for 10 years.
Step-by-step explanation:
The requirement for keeping Rx records under Medicare Part D is for a uniform duration regardless of the form they are kept in; both original and electronic records must be maintained for a period of 10 years. This mandate ensures that prescription drug history is adequately recorded and can be audited or reviewed for accuracy and compliance with regulations. It is important for pharmacies and healthcare providers to adhere to this requirement to maintain integrity and accountability in the dispensing of prescription medications to Medicare beneficiaries.