Common DOT Return to Duty Acronyms

Short Answer

The DOT Return to Duty process uses a dense set of acronyms drawn from 49 CFR Part 40, the FMCSA Clearinghouse rule, and the agencies that administer the program. The table below defines the acronyms a driver, employer, or DER is most likely to encounter.

Acronym Reference Table

Acronym	Stands For	What It Means
SAP	Substance Abuse Professional	Evaluates an employee who violated a DOT drug or alcohol rule and makes recommendations for education, treatment, follow-up testing, and aftercare.
MRO	Medical Review Officer	A licensed physician who reviews laboratory drug test results and evaluates medical explanations for certain results.
DER	Designated Employer Representative	The employer's authorized representative who removes employees from safety-sensitive duty and receives test results and SAP reports.
C/TPA	Consortium/Third-Party Administrator	A service agent that administers or coordinates drug and alcohol testing programs for one or more employers.
BAT	Breath Alcohol Technician	Instructs and assists employees during alcohol testing and operates an EBT.
STT	Screening Test Technician	Instructs and assists employees during alcohol testing and operates an ASD.
ASD	Alcohol Screening Device	The device used for the initial alcohol screening test, operated by a BAT or STT.
EBT	Evidential Breath Testing device	The device used for evidential (confirmation) alcohol testing, operated only by a BAT.
CCF	Federal Custody and Control Form	The form used to document chain of custody for a DOT drug test specimen, from collection through laboratory testing.
ATF	Alcohol Testing Form	The form used to document a DOT alcohol test, from screening through confirmation.
RTD	Return to Duty	The regulatory process and the specific test an employee must complete before resuming safety-sensitive duties after a violation.
CDL	Commercial Driver's License	The license classification required to operate a commercial motor vehicle, tracked in the FMCSA Clearinghouse.
FMCSA	Federal Motor Carrier Safety Administration	The DOT agency that regulates commercial motor carriers and CDL holders, and that administers the Clearinghouse.
ODAPC	Office of Drug and Alcohol Policy and Compliance	The office within the Office of the Secretary of Transportation that coordinates DOT drug and alcohol testing policy.
HHS	Department of Health and Human Services	The federal department whose Mandatory Guidelines govern laboratory certification for DOT-regulated drug testing.
SAMHSA	Substance Abuse and Mental Health Services Administration	The HHS agency that certifies the laboratories used for DOT-regulated drug testing.
NTSB	National Transportation Safety Board	A federal agency that can request access to SAP reports and related records in connection with its accident investigations.

Applicable Regulations and Sources

The definitions above are drawn from 49 CFR § 40.3 and related sections of 49 CFR Part 40, plus generally established descriptions of the federal agencies involved in DOT drug and alcohol testing.

Professional Observation

One issue I often see is a driver or employer using two acronyms interchangeably, most commonly ASD and EBT, or SAP and MRO. These are different roles and different devices with different rules attached to each. Confusing them can lead to a misunderstanding about what step of the process is actually happening.

Primary Authorities

49 CFR § 40.3, Definitions

Need Help Understanding Your Paperwork?

If an acronym on a form or in a letter from your employer is unclear, a DOT qualified Substance Abuse Professional can explain exactly what it means for your case.

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Reviewed by: Perret deLapouyade, CEAP, SAP
Reviewed date: July 12, 2026
Updated date: July 12, 2026
BOK ID: BOK-0092