Short Answer

Six operating administrations within the U.S. Department of Transportation, plus the U.S. Coast Guard, use the Return to Duty process described in 49 CFR Part 40: the Federal Motor Carrier Safety Administration (FMCSA), the Federal Aviation Administration (FAA), the Federal Railroad Administration (FRA), the Federal Transit Administration (FTA), the Pipeline and Hazardous Materials Safety Administration (PHMSA), and the United States Coast Guard (USCG). Each agency regulates drug and alcohol testing for safety-sensitive employees in its own transportation mode, but all of them apply the same core procedures set out in Part 40.

How the Agencies Relate to Part 40

49 CFR Part 40 is not specific to any single mode of transportation. It is the DOT-wide procedural rule that governs how drug and alcohol tests are conducted, how results are reviewed, and how the SAP and Return to Duty process works, regardless of which agency's rule brought the employee into the testing program in the first place. Each DOT agency then has its own regulation that determines who must be tested, under what circumstances, and how the mode-specific program is administered.

The exact job titles and circumstances covered within each mode are defined by that agency's own regulation. Anyone unsure whether a specific position is covered should confirm with the applicable agency or their employer rather than assume based on job title alone.

Applicable Regulations

49 CFR Part 40 sets the uniform procedures used by all six of these authorities. FMCSA's mode-specific rule is found at 49 CFR Part 382. The other agencies maintain their own mode-specific parts of Title 49 of the Code of Federal Regulations. Because this research pass verified detailed section numbers only for Part 40 and select portions of Part 382, readers should confirm the exact section numbers for FAA, FRA, FTA, PHMSA, or USCG rules directly with the applicable agency or their DOT-qualified SAP.

Common Misconception

Misconception

49 CFR Part 40 is an FMCSA regulation written specifically for truck and bus drivers.

Reality

Part 40 is a DOT-wide regulation shared by all six agencies listed above. FMCSA has its own separate mode-specific rule, 49 CFR Part 382, which works alongside Part 40 for commercial drivers. Part 40 itself is not owned by any single agency.

Why the Confusion Occurs

Commercial driver testing under FMCSA is the most visible and frequently discussed application of the DOT testing program, so people sometimes assume Part 40 was written for that mode alone.

Frequently Asked Questions

Does the Return to Duty process differ by agency?
The core SAP and Return to Duty procedures in Part 40 apply the same way across agencies. Differences tend to appear in agency-specific rules about who is covered and how certain program details, such as the Clearinghouse for FMCSA-regulated drivers, are administered.

Is there a single DOT agency that oversees all of these programs?
The Office of Drug and Alcohol Policy and Compliance (ODAPC), within the Office of the Secretary of Transportation, coordinates drug and alcohol testing program matters across the Department, while each operating administration enforces the rules within its own mode.

Related Articles

• What Is the DOT Return to Duty Process?
• Who Is Required to Complete the Return to Duty Process?
• DOT Agencies Covered by Drug and Alcohol Testing Rules
• Understanding 49 CFR Part 40
• What Is the FMCSA Drug and Alcohol Clearinghouse?

Primary Authorities

• 49 CFR Part 40 (procedures for transportation workplace drug and alcohol testing programs)
• 49 CFR Part 382 (FMCSA controlled substances and alcohol use and testing)

Need to Begin the DOT SAP Process?

Whichever DOT agency regulates your position, the Return to Duty process starts the same way: an evaluation with a DOT-qualified Substance Abuse Professional.

Schedule an Initial SAP Assessment