On March 10, Senators Rand Paul, Cory Booker and Kirsten Gillibrand introduced a Senate bill to legalize medical marijuana under federal law. Most importantly, the bill requires the Drug Enforcement Administration (DEA) to reschedule marijuana from Schedule I to Schedule II under the Controlled Substances Act.

This change to the United States’s contradictory and confusing marijuana laws is long overdue.

Federal law currently outlaws marijuana for all purposes. Many states, however, have legalized possession, production and use for medical or recreational purposes. The federal government maintains that federal law preempts state law, implying federal authorities can enforce federal prohibition everywhere, regardless of state law.

Yet federal authorities currently take a hands-off approach to marijuana purchase and sale when these acts do not violate state laws. Cross-border traffic between legalized and non-legalized states creates further ambiguity. This means that federal law applies differently across different states and that, more generally, the federal government is often choosing not to enforce a federal law.

The federal government has several options for addressing this incoherence. At one extreme, the Drug Enforcement Administration and other federal authorities could resume vigorous enforcement of federal marijuana prohibition throughout the country. At the other extreme, Congress could eliminate federal marijuana prohibition by removing marijuana from the list of federally controlled substances.

The first approach is ill-advised for many reasons. Such an approach would require substantial new expenditure and yet have limited impact on marijuana use, based on past experience. Re-escalation would drive the marijuana market back underground, with the attendant violence and corruption of black markets. It would also conflict with growing popular support for marijuana legalization.

The second option—repealing marijuana prohibition—is appealing and is the only approach that would eliminate the conflicts and contradictions in existing law. But federal legalization may not yet be politically feasible, so intermediate approaches merit consideration.

A reasonable compromise is for Congress to force the Drug Enforcement Administration to reschedule marijuana under the Controlled Substance Act (CSA), the federal law that currently governs federal marijuana prohibition.

The CSA puts known drugs into one of five schedules, with Schedule I being the most restrictive and Schedule V the least. The DEA defines Schedule I drugs as substances “with no currently accepted medical use and a high potential for abuse.” They are “the most dangerous drugs of all the drug schedules with potentially severe psychological or physical dependence.” Examples include heroin, LSD, ecstasy and, yes, marijuana.

Schedule II drugs have “less abuse potential than Schedule I drugs,” but “are also considered dangerous,” these include methamphetamine, Oxycontin, Adderall and others.

Putting pot in Schedule I is bizarre. Few observers believe either that marijuana has “no currently accepted medical use” or that it has “a high potential for abuse,” and many believe it’s safer than the drugs in Schedules I and II.

The DEA has the power to reschedule marijuana on its own, but it has so far refused to do so. This, despite the fact that in 1988 the DEA administrative law judge Francis Young ruled that, “Marijuana, in its natural form, is one of the safest therapeutically active substances known to man. By any measure of rational analysis marijuana can be safely used within a supervised routine of medical care.” He recommended that it be “transferred from Schedule I to Schedule II.”

But DEA administrator John Lawn overruled Young’s decision, and two Court of Appeals decisions have upheld the DEA’s authority to maintain the current classification. Thus congressional action is likely necessary to force the DEA’s hand.

Rescheduling marijuana from Schedule I to Schedule II would mean that medical provision in current or future medical marijuana states would not be inconsistent with federal law. And if federal authorities allow physicians reasonable leeway in prescribing marijuana, consistent with current practice in medical marijuana states like California and Colorado, the black market for marijuana would shrink substantially.

Rescheduling does not conflict with international drug treaties, since many substances covered by those treaties are in Schedule II or higher. And federal medicalization would reduce existing barriers to research on the possible health benefits of marijuana.

Federal medicalization is far from a perfect policy. Under medicalization, the federal government might still practice de facto prohibition by interfering with physicians’ ability to prescribe marijuana, as occurs now with other Schedule II drugs. And if federal prescribing restrictions were substantial, the black market for marijuana would re-emerge. Further, treating marijuana as medicine, rather than like other commodities, might impede taxation (this occurs now, partially, in Colorado).

This approach is imperfect because it still restricts legal access to marijuana, rather than respecting the right of every individual to consume marijuana or not. Rescheduling marijuana into Schedule II would also not eliminate conflict between federal and state marijuana laws; full legalization, as in Colorado, Washington, Oregon, Alaska and the District of Columbia, would still be inconsistent with federal law.

But medicalization via rescheduling is nevertheless a substantial improvement over current policy: It reduces the black market for marijuana, scales back enforcement expenditure, and rationalizes current law, all while freeing many marijuana users from ill-advised legal threats and penalties.

Congress should act now and allow this much-needed reform.