Under federal law (applicable in all states) it is illegal for a person to knowingly or intentionally possess a controlled substance, unless the substance was obtained through a valid prescription or order from a practitioner, while acting in the course of the practitioner’s professional practice. See 21 U.S.C. §844.

The term controlled substance means a drug or other substance—or an immediate precursor to the drug or other substance—that is included in schedule I, II, III, IV, or V of the relevant portion of the United States Code (statute). See 21 U.S.C. §841.

The term practitioner means a physician, dentist, veterinarian, scientific investigator, pharmacy, hospital, or other person licensed, registered, or otherwise permitted by the United States or the jurisdiction (state) in which he practices or does research to distribute, dispense, conduct related research, administer, or use in teaching or chemical analysis a controlled substance in the course of such professional practice or research. 21 U.S.C. §802(21).

As under federal law, state laws usually classify substances in groups or schedules that determine which substances are included in the definition of controlled substances, and the potential penalties or punishments for possessing them without legal authorization. Criminal charges and penalties for these offenses vary from state to state and are usually located in a state’s statutes—often in the penal or criminal code. Illegal possession of controlled substances may also be prosecuted under federal law. See 21 U.S.C. §844.

Under both federal and Montana state law, it is illegal to possess a controlled substance without a valid prescription or order from a licensed practitioner. Controlled substances are classified into five schedules (I-V) based on their potential for abuse, with Schedule I substances having the highest potential for abuse and no accepted medical use. In Montana, the penalties for possession of a controlled substance depend on the type and amount of the substance, as well as the individual's criminal history. Possession of small amounts may be charged as a misdemeanor, while larger amounts or possession with intent to distribute can result in felony charges. Additionally, federal law also prohibits the possession of controlled substances, and individuals may face federal charges, which can carry severe penalties including fines and imprisonment. It is important for individuals in Montana to understand both state and federal regulations regarding controlled substances to ensure compliance with the law.