Final answer:
Controlled substance records must be kept for a minimum of two years as per DEA regulations, which fall under the Controlled Substances Act, with potential for states to require longer retention.
Step-by-step explanation:
According to the Drug Enforcement Administration (DEA), records of controlled substances must be maintained for a minimum of two years. This requirement comes under the Controlled Substances Act and is enforced at the federal level. It is crucial for any entity that dispenses, administers, or otherwise handles controlled substances to be aware of and comply with these regulations to avoid legal complications. These records often include, but are not limited to, receipts, inventories, prescriptions, and records of dispensed drugs. It's important to note that some states may have more stringent requirements, necessitating the maintenance of records for a longer period.