Exactly How Legal is Legal Marijuana? Here’s What You Need to Know

two women cooking in a kitchen while smoking cannabis
Darrin Harris Frisby/Drug Policy Alliance

Note: The information in this article is current as of January, 2017. The legalization of cannabis is a fast-moving issue so be sure to check your state and local laws for the most up-to-date-information.

2018 ushered in the much-anticipated legalization of marijuana sales in California and, later this year, Massachusetts.

At least 12 more states are considering legalizing cannabis in the coming year, making marijuana more legally accessible than ever before in U.S. history.

But even though marijuana is legal in many states, you could still get arrested, fined or go to jail for possessing it if you don’t follow the letter of the law.  

If you aren’t sure what cannabis regulations apply where you are, don’t try to wing it. Call the non-emergency number of your local police department and ask.

When Did Marijuana Get So Popular Anyway?

Cannabis may be making headlines now, but its use is certainly nothing new.

People consumed marijuana as far back as 2727 B.C., according to the Drug Enforcement Administration,  

Despite its current level of nationwide acceptance, cannabis hasn’t always had such widespread legislative support.  

The federal government first began imposing limitations on marijuana at the state level in 1937.

But by 1973, states pushed back by relaxing state laws on the criminalization of cannabis.

California further blazed the trail in 1996, becoming the first state to legalize medical cannabis.

Today, eight states and the District of Columbia allow people to possess small amounts of cannabis for adult recreational use.

Twenty-nine states, the District of Columbia, Guam and Puerto Rico allow people to possess cannabis for medical use.

A total of 22 states have decriminalized possessing small amounts of marijuana, meaning arrests are treated as a civil or local violation rather than a state crime.

With support for legalizing marijuana use in the U.S. at an all-time high, state decriminalization or legalization laws are likely to pop up all across the country in coming years.

Why the shift in the government’s attitude toward something it still considers as dangerous as heroin, LSD and peyote?

The short answer is the feds have more important stuff to worry about than whether someone grabs a quick puff in the privacy of their own home before heading to bed.

That’s not to say they’ve given up completely. After all, cannabis is still illegal at the federal level.

However, in 2013, the U.S. Department of Justice decided to focus its marijuana enforcement efforts on what it considers higher priorities, like:

  • Keeping marijuana out of the hands of minors
  • Preventing people from driving while high
  • Keeping marijuana use off federal property
  • Preventing state-authorized marijuana activity from becoming a cover for drug trafficking

If you live in or plan to visit a state where possession of cannabis is legal, there are a few important things to keep in mind before you head to the nearest dispensary.

But first, let’s get some definitions out of the way so we’re all on the same page.

Medical cannabis: Patients with a doctor’s recommendation can buy cannabis at a dispensary or grow their own.

Recreational cannabis: In states where it’s legal, people 21 or older can purchase and possess a specified amount of cannabis. Rules and regulations on recreational cannabis vary by state.

Toking While Traveling

Traveling across state lines with cannabis from a location where it’s legal to a place where it’s not is technically against federal law.

Attorney Christopher Coble says crossing state lines with marijuana “could lead to a federal drug trafficking charge, depending on how much you have in your possession. Thus far, the federal government has left the bulk of marijuana prosecutions to the states, but that isn’t always guaranteed.”

Drug trafficking charges are nothing to sneeze at. Your first offense could land you five years in jail and a $250,000 fine. Penalties for subsequent fines are even more serious.

If you need cannabis for medical reasons, consult with your physician or an attorney on the safest way to travel with it.

If you’re thinking of traveling with cannabis for recreational purposes, you’re better off leaving it at home.


If you’re flying from an airport in a state where cannabis is legal, you may be asked to dispose of your marijuana before going through a TSA checkpoint.

Or maybe not.

Airports are subject to federal law, and TSA is a federal agency so technically cannabis is not allowed on the property.

On the other hand, according to TSA policy “TSA security officers do not search for marijuana or other drugs. In the event a substance that appears to be marijuana is observed during security screening, TSA will refer the matter to a law enforcement officer.

Then what happens?

“We’re really not in a place to do anything,” Sgt. Ray Kelly of the sheriff’s office in Alameda County, California, admitted to CNBC.


Amtrak, the nationwide railway system, has a very strict policy against cannabis.

“The use or transportation of marijuana for any purpose is prohibited, even in states where recreational use is legal or permitted medically.”


As mentioned above, the federal government is pretty serious about preventing people from driving while under the influence of marijuana.

Each state where cannabis possession is legal has its own rules about driving around with marijuana in your car. However, no state allows drivers to consume it while behind the wheel.

In fact, it’s even illegal in some states for passengers to consume pot while in a motor vehicle.

That said, evaluating drivers for driving under the influence of marijuana is a difficult task for law enforcement.

There are currently no reliable standard DUI field tests on the market for police officers to determine if someone is too high to drive.

“Some police departments use drug recognition experts, specially trained officers dispatched to evaluate suspected drugged drivers,” notes Beth Schwartzapfel at The Marshall Project.

But even those assessments are of dubious quality since the officers have no medical training.

As a result, gathering hard data on drugged driving is difficult, making studies on cannabis-related auto accidents inconsistent.

Two high-profile reports released in 2017 on marijuana’s effect on drivers came to different conclusions.

An American Journal of Public Health study found no significant increase in automobile fatalities in two states where cannabis is legal, compared to eight states where it isn’t.

Meanwhile, a Highway Loss Data Institute report found a 3% increase in car insurance collision claims in three states where recreational cannabis is permitted.  

The National Institute on Drug Abuse is also unclear whether marijuana use affects driving.

“Several meta-analyses of multiple studies found that the risk of being involved in a crash significantly increased after marijuana use — in a few cases, the risk doubled or more than doubled. However, a large case-control study conducted by the National Highway Traffic Safety Administration found no significant increased crash risk attributable to cannabis after controlling for drivers’ age, gender, race, and presence of alcohol,” says the Institute.

Weed at Work

There aren’t many (or any, really) career counselors who would advise people to go to work high just for kicks.

On the other hand, companies aren’t required to have drug-free workplace policies in place unless they are federal contractors or receive federal grants.

However, federal law gives employers the right to perform drug testing, and cannabis is still illegal under federal law.

“In June of 2015, the Colorado Supreme Court upheld the ruling of the trial court and ruled that an employer is still permitted to terminate an employee who engages in activity that violates federal law,” notes the National Association of Colleges and Employers.

In the end, it’s up to individuals to decide if recreationally using cannabis on the job is a responsible thing to do.

Depending on the nature of your job, it’s possible that working under the influence of cannabis may put you at greater risk for and on-the-job injury.

That could open a whole can of worms since many companies insist employees immediately take a drug test if they’re injured at work.

But the test results may not matter in the long run.

The Occupational Safety and Health Administration contends that mandatory drug testing following an on-the-job injury could be considered a retaliatory action that violates the law.

“For substances other than alcohol, currently available tests are generally unable to establish a relationship between impairment and drug use. Employers should be aware that post-incident drug testing will not necessarily indicate whether drug use played a direct role in the incident,” says OSHA.

To make things even more complicated, companies that terminate an employee with medical documentation that recommends the use of cannabis for medical reasons may be in violation of the ADA.

Get Taxed for Toking

two men sitting outside smoking
Darrin Harris Frisby/Drug Policy Alliance

One reason states are eager and willing to make cannabis legal is so they can tax the heck out of it and rake in the dough.

In fact, Colorado collected so much tax money the first year cannabis was legal the state actually had to give some of it back to taxpayers.

If you’re planning to legally buy marijuana, take a look at the tax rates of some states where marijuana possession is permitted and budget accordingly.

  • Washington: 37%

What Have You Got to Lose?

Legal or not, possession of cannabis can have some unintended consequences.

  • People purchasing medical marijuana in Pennsylvania or Hawaii are required to turn in all firearms they own.

The laws surrounding the legal purchase and possession of cannabis change quickly.

One of the best ways to stay in the know is by joining cannabis advocacy groups like NORML or the Marijuana Policy Project so you don’t accidentally run afoul of the law.

Lisa McGreevy is a staff writer at The Penny Hoarder.