The Department of Transportation (DOT) requires that employees who have violated the DOT drug and alcohol regulations undergo a follow-up test and return-to-duty test as part of the process to return to safety-sensitive duties. A follow-up test is a drug and/or alcohol test that is conducted after an employee has completed their initial treatment program for a substance abuse problem. The test is used to monitor the employee’s continued abstinence from drugs and alcohol and to ensure their fitness for duty. The number and frequency of follow-up tests are determined by the Substance Abuse Professional (SAP) who oversees the employee’s treatment. A return-to-duty test is a drug and/or alcohol test that is conducted after an employee has completed their initial treatment program and has been evaluated by a SAP. The test is used to determine if the employee is fit to return to safety-sensitive duties. The return-to-duty test must be negative before the employee can resume their safety-sensitive duties. Both the follow-up test and the return-to-duty test must be conducted in accordance with DOT regulations, using approved testing methods and laboratories. The results of these tests are confidential and are only released to the employer and the SAP who is overseeing the employee’s treatment. The follow-up test and return-to-duty test are critical components of the DOT drug and alcohol testing program, as they ensure that employees who have violated the regulations receive the necessary treatment and monitoring to ensure their fitness for duty and the safety of the public.