What Does a DOT Substance Abuse Professional Do?

A Substance Abuse Professional (SAP) evaluates employees who have violated a DOT drug and alcohol regulation and makes recommendations concerning education, treatment, follow-up testing and aftercare, according to the definition in 49 CFR 40.3. Under 49 CFR 40.285, an employee with a violation cannot again perform DOT safety-sensitive duties for any employer until completing the SAP evaluation, referral and education or treatment process, and the rule states that the first step in this process is a SAP evaluation.

Section 40.291(a) lists the SAP's duties. The SAP makes a clinical assessment and evaluation to determine what assistance the employee needs to resolve problems associated with alcohol or drug use, refers the employee to an appropriate education or treatment program, and conducts a follow-up evaluation to determine whether the employee actively participated and demonstrated successful compliance. The SAP also provides the Designated Employer Representative (DER) with a follow-up testing plan and gives the employee and employer recommendations for continuing education or treatment.

Under 40.291(b), the SAP is "not an advocate for the employer or employee." The rule states that the SAP's function is "to protect the public interest in safety by professionally evaluating the employee and recommending appropriate education/treatment, follow-up tests, and aftercare." In a notification published March 4, 2026 (91 FR 10518), DOT described the SAP as the "gatekeeper" for its return-to-duty process.

Under 49 CFR 40.293(g), the SAP must not consider a claim that the test was unjustified or inaccurate, or statements that attempt to mitigate the seriousness of the violation, such as assertions of "medical marijuana" use or poppy seed ingestion, when making a recommendation. How an MRO treats a state medical marijuana card when verifying a result is covered in Does a State Medical Marijuana Card Excuse a Positive DOT Drug Test?. Under 49 CFR 40.305(c), the SAP does not make a "fitness for duty" determination as part of the re-evaluation unless a DOT agency regulation requires one, and the decision to return the employee to safety-sensitive duty belongs to the employer.

The full return-to-duty sequence is covered in What Is Required Before a Driver Returns to Duty after a DOT Violation?.

The SAPs category of the MyDrugTesting.com directory lists providers that offer SAP services, with each listing's location.