Last Updated on July 16, 2026 by MyHRConcierge

As marijuana laws continue to evolve, many employers are questioning what the federal government’s move to reclassify medical marijuana means for workplace drug testing- especially in safety-sensitive industries.

The answer from the U.S. Department of Transportation (DOT) is straightforward: nothing has changed for DOT-regulated employees. Despite the Trump administration’s recent move to federally reclassify state-regulated medical marijuana, commercial truck drivers, airline pilots, railroad employees, transit operators, pipeline workers and other safety-sensitive transportation employees are still prohibited from using marijuana, even if it is authorized under a state’s medical marijuana program.

For employers in the transportation industry, this clarification reinforces the importance of maintaining compliant drug testing policies and educating employees on the distinction between evolving cannabis laws and existing federal transportation regulations.

The DOT’s Position Remains Unchanged

Following the Department of Justice’s order to move state-regulated medical marijuana from Schedule I to Schedule III of the Controlled Substances Act (CSA), the DOT issued new guidance clarifying that the rescheduling does not change its drug and alcohol testing requirements.

The agency stated plainly:

“Marijuana use is not compatible with safety-sensitive functions.”

The guidance reiterates that DOT-regulated employers must continue following existing federal drug testing regulations, regardless of changes to marijuana’s classification under the CSA.

Medical Marijuana Is Still Not a Valid Explanation for a Positive Drug Test

One of the most significant clarifications involves the role of Medical Review Officers (MROs). Under current DOT regulations, an MRO cannot verify a laboratory-confirmed positive marijuana test as negative simply because an employee used medical marijuana through a state-approved program.

Even if an employee provides a state-issued medical marijuana card, a  physician’s recommendation or certification or dispensary receipts or purchase records, those documents do not qualify as a “legitimate medical explanation” under federal drug testing regulations.

According to the DOT, this is because marijuana dispensed through state medical cannabis programs has not been approved by the U.S. Food and Drug Administration (FDA) and therefore cannot be considered a federally prescribed controlled substance.

Who Does This Affect?

DOT drug and alcohol testing regulations apply to employees performing safety-sensitive duties across several transportation industries, including:

• Commercial truck drivers regulated by the Federal Motor Carrier Safety Administration (FMCSA)
• Airline pilots and aviation personnel regulated by the Federal Aviation Administration (FAA)
• Railroad employees
• Public transit operators
• Pipeline workers
• Maritime transportation employees

These workers remain subject to federal drug testing requirements regardless of state medical marijuana laws.

Why Employers Shouldn’t Assume Federal Rescheduling Changes Workplace Rules

The federal rescheduling effort has generated considerable confusion because different federal agencies are responding in different ways. For example, several agencies have begun preparing for regulatory changes associated with marijuana’s Schedule III status, including potential tax, licensing and administrative updates affecting the cannabis industry.

However, the DOT has emphasized that its guidance simply clarifies existing federal requirements for safety-sensitive transportation workers. The agency also notes that its guidance does not create new law, but instead explains how current regulations continue to apply following the rescheduling order. For employers, the practical takeaway is that DOT compliance obligations remain unchanged.

What Transportation Employers Should Do

Transportation employers should continue administering DOT-compliant drug and alcohol testing programs while proactively communicating expectations to employees.

Best practices include:

• Reviewing workplace drug and alcohol policies regularly.
• Clearly stating that marijuana remains prohibited for DOT-regulated safety-sensitive positions, including medical marijuana.
• Training supervisors on reasonable suspicion procedures and DOT compliance requirements.
• Ensuring employees understand that state legalization does not override federal transportation regulations.
• Partnering with qualified drug testing providers to remain compliant with evolving federal requirements.

Regular policy reviews can also help reduce confusion as cannabis laws continue to change across the country.

The Ongoing Challenge for Multi-State Employers

Many employers now operate in states where medical or recreational marijuana is legal, while also employing workers subject to federal transportation regulations.

This creates a layered compliance landscape. Employers may have different drug testing obligations depending on whether an employee performs a DOT-regulated safety-sensitive function or works in a non-regulated position that is governed primarily by state employment laws.

Developing clear, position-specific policies and working with experienced HR and compliance professionals can help employers navigate these overlapping legal requirements.

Final Thoughts

While the federal government’s move to reclassify medical marijuana marks a significant shift in cannabis policy, it does not change the rules for DOT-regulated safety-sensitive employees. Commercial drivers, pilots, railroad workers, transit operators and other covered employees remain prohibited from using marijuana- even when it is legally obtained through a state medical marijuana program.

For transportation employers, now is an excellent time to review drug testing policies, educate employees and ensure compliance programs remain aligned with current DOT requirements. As federal cannabis policy continues to evolve, staying informed will be essential for reducing compliance risks while maintaining workplace safety.

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