Marijuana—also known as marihuana or cannabis—is classified as a controlled substance under federal law, and its possession, use, and distribution is illegal. See 21 U.S.C. §812.

But many states have recently passed laws that generally legalize marijuana in some form. For example, Alaska, California, Colorado, Illinois, Maine, Massachusetts, Michigan, Nevada, Oregon, Vermont, and Washington have enacted laws legalizing marijuana for recreational use.

The District of Columbia allows all citizens over the age of 21 to possess up to two ounces of marijuana, to use and grow marijuana on private property, and to exchange marijuana between persons as long as no money, goods, or services are exchanged.

And some states that do not allow recreational use of marijuana do allow limited use of marijuana to treat symptoms of illness and other conditions—known as medical marijuana. States that allow limited use of medical marijuana include Arkansas, Arizona, Connecticut, Delaware, Florida, Hawaii, Louisiana, Maryland, Massachusetts, Minnesota, Missouri, Montana, New Hampshire, New Jersey, New Mexico, New York, North Dakota, Ohio, Oklahoma, Pennsylvania, Rhode Island, Utah, Vermont, and West Virginia. The medical marijuana laws in some of these states are broader than others, with some states only allowing use of cannabis-infused products such as oils and pills. Federal law prohibits health care practitioners from writing a prescription for medical marijuana, so practitioners in medical marijuana states write a recommendation for medical marijuana.

Other states have not legalized marijuana, but have decriminalized it—meaning possession of small amounts of marijuana is not punishable by jail or prison time, but may be punished with a fine. States that have decriminalized possession of marijuana under limited circumstances include Connecticut, Maryland, Mississippi, Nebraska, New Hampshire, New Mexico, New York, North Carolina, and Virginia.

Marijuana laws are generally located in a state’s statutes—often in the penal or criminal code, or in the health and safety code.

In Virginia, marijuana has been decriminalized under certain circumstances. This means that possession of small amounts of marijuana is not subject to criminal penalties such as jail or prison time, but it may result in a fine. As of the knowledge cutoff in 2023, Virginia has also passed laws that allow for the possession and use of marijuana for adults 21 years and older. Adults in Virginia can possess up to one ounce of marijuana and are also allowed to cultivate up to four cannabis plants per household for personal use. However, public use and distribution of marijuana remain illegal. Additionally, Virginia has a medical marijuana program that permits the use of cannabis for treating specific medical conditions, as recommended by a registered practitioner. It's important to note that despite state laws, marijuana remains a controlled substance under federal law, and its possession, use, and distribution are illegal under federal statutes. Therefore, there can be legal conflicts between state and federal law regarding marijuana activities.