Quick Answer

The U.S. Coast Guard regulates chemical testing in the maritime industry through 46 CFR Part 16 and related marine-safety rules. Part 40 applies to drug testing under Part 16, while maritime casualty testing and credential actions can create separate obligations.

Governing Rules

The controlling industry rule is 46 CFR Part 16, used with 49 CFR Part 40.

Who Is Covered

• Crewmembers required by a vessel's Certificate of Inspection or engaged or employed on board a vessel owned in the United States when Part 16 applies.
• Individuals performing safety-sensitive duties directly affecting the safe operation of a vessel.
• Prospective crewmembers subject to required pre-employment testing.

Who Is Not Automatically Covered

• Every marina, port, or shoreside employee.
• A person solely because the person possesses a Merchant Mariner Credential.
• A maritime test conducted exclusively under a private policy without Federal authority.

What Triggers the SAP Return-to-Duty Process

A verified positive or refusal under the Coast Guard’s DOT-regulated drug-testing program requires removal and completion of the applicable Part 40 SAP process. Maritime alcohol events can arise under different Coast Guard authorities, including serious-marine-incident and operating-under-the-influence rules. The applicable regulation and testing authority should be identified before describing the event as a Part 40 SAP case.

Return-to-Duty Process

The employee completes a SAP evaluation and the recommended education or treatment, then returns to the same SAP for a follow-up evaluation. After the SAP reports successful compliance, the employer must ensure the required return-to-duty test is completed. A return-to-duty drug test must be conducted under direct observation under 49 CFR § 40.67. An applicable return-to-duty alcohol test must produce a result below 0.02 under 49 CFR § 40.305. Only the employer can return the person to covered duty. Follow-up testing occurs after the employee has successfully completed the SAP process and returned to safety-sensitive work. The SAP establishes the follow-up testing plan; the employer is responsible for implementing it, and the employee must comply with required follow-up tests while performing safety-sensitive duties. Follow-up drug tests are directly observed; alcohol follow-up tests are not specimen collections under direct observation. 49 CFR § 40.307 and 49 CFR § 40.309 If the employee leaves DOT-regulated employment before the plan is completed, the remaining requirement does not disappear. A subsequent DOT employer that places the employee into safety-sensitive duties must continue the remaining plan.

Employer Responsibilities

• Correctly identify covered employees and tests.
• Remove a violator from safety-sensitive functions and provide the required SAP information.
• Order the return-to-duty test only after receiving successful-compliance documentation.
• Implement the SAP's follow-up plan without disclosing the schedule.
• Meet industry-specific reporting, recordkeeping, contractor, and oversight duties.

Employee Responsibilities

• Confirm whether the test was DOT or non-DOT and which authority applied.
• Stop performing covered safety-sensitive functions after a DOT violation.
• Complete the SAP's education or treatment recommendation and follow-up evaluation.
• Work with a current or prospective employer for the return-to-duty test; a SAP does not order the test.
• Comply with unannounced follow-up testing after returning to covered duty.

Agency- or Program-Specific Nuances

• Marine employers have Part 16 duties for pre-employment, random, reasonable-cause, and return-to-duty/follow-up drug testing.
• A serious marine incident may trigger separate chemical-testing requirements under 46 CFR Part 4.
• A drug-test result or refusal can affect a Merchant Mariner Credential through separate Coast Guard reporting and credential processes; SAP completion does not itself resolve credential status.
• Employers must confirm both employment testing eligibility and any credential requirements applicable to the duty.
• Coast Guard drug cases can include an additional MRO return-to-work determination. Before an individual who failed a required dangerous-drug test may return to work aboard a vessel, 46 CFR § 16.201(f) requires an MRO to determine that the individual is drug-free and that the risk of subsequent dangerous-drug use is sufficiently low to justify return to work. This determination is separate from the DOT SAP’s successful-compliance report. The SAP does not replace the MRO determination, and the MRO does not replace the Part 40 SAP process.

Common Misconceptions

• Holding an MMC does not make every shoreside job DOT-covered.
• The Coast Guard program is not administered by FMCSA's Clearinghouse.
• Completing the SAP process does not automatically restore a suspended or otherwise affected credential.

Related Articles

• Alcohol Violations and Testing
• Direct Observation
• Transportation Modalities Hub

Frequently Asked Questions

Is the Coast Guard MRO return-to-work determination the same as the SAP report?

No. The SAP evaluates the employee under Part 40, determines successful compliance with the prescribed education or treatment, and establishes the follow-up testing plan. The MRO makes the separate maritime return-to-work determination required by 46 CFR §16.201(f).

Does Part 40 itself decide which jobs are covered?

No. The operating administration's industry rule identifies covered employers and safety-sensitive functions. Part 40 supplies the testing procedures and SAP return-to-duty framework.

Can an employee return to safety-sensitive duty immediately after the SAP follow-up evaluation?

No. An employer must receive the SAP's successful-compliance report and obtain the required negative return-to-duty test result before safety-sensitive duty resumes.

Who decides whether to return an employee to work?

The employer makes the employment and safety-sensitive assignment decision. A SAP evaluates compliance and recommends follow-up testing but does not order an employer to hire or reinstate someone.

Need Help With the DOT Return-to-Duty Process?

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