Before practicing medicine as a solo practitioner, you must be issued a certificate to prescribe controlled substances by the U.S. Department of Justice’s Drug Enforcement Administration. Certificates are issued for practice in specific locations, so you must first obtain a license to practice in a given state. Learn more about the process of obtaining a DEA Certificate at the Drug Enforcement Administration’s website.
Some states may also require a special license or certificate for prescribing controlled substances. This is something about which you will learn more during your post-graduate medical education.