President Donald Trump signed an executive order Thursday directing federal agencies to reclassify marijuana, loosening long-standing restrictions on the drug and marking the most consequential shift in U.S. cannabis policy in more than half a century.

The order, once finalized by the Drug Enforcement Administration, moves cannabis out of Schedule I classification — the most restrictive category under the Controlled Substances Act, alongside heroin and LSD — to a Schedule III classification, which encompasses substances with accepted medical use and a lower potential for abuse, such as ketamine and Tylenol with codeine.

“This action has been requested by American patients suffering from extreme pain, incurable diseases, aggressive cancers, seizure disorders, neurological problems and more, including numerous veterans with service related injuries, and older Americans who live with chronic medical problems that severely degrade their quality of life,” Trump said from the Oval Office Thursday.

Also on Thursday, the Centers for Medicare and Medicaid Services, led by Dr. Mehmet Oz, is expected to launch a pilot program in April enabling certain Medicare-covered seniors to receive free, doctor-recommended CBD products, which must comply with all local and state laws on quality and safety, according to senior White House officials. The products must also come from a legally compliant source and undergo third-party testing for CBD levels and contaminants.