If you are a seasonal employer of CDL drivers, you need to understand this overlooked and misunderstood DOT requirement.

DOT-regulated employees who are not in a drug testing pool for more than 30 days must pass a pre-employment drug test when they are re-hired.

Even if your seasonal employees are not DOT-regulated, this is good practice.

So if they are laid off for the winter, for example, they need a pre-employment drug test when rehired in the spring.

BUT, if a driver is available to perform safety-sensitive duties (i.e. drive a vehicle that requires a CDL) — even in the “off season” – s/he must remain enrolled in a random testing pool. So, if an employee is “on call,” then keep him enrolled.


Some of our seasonal employers keep their drivers in the pool in the off season, and have them tested if selected, even if not driving. Others take them out and test on re-hire.

Here is the rule:


Question 3: Is a pre-employment controlled substances test required if a driver returns to a previous employer after his/her employment had been terminated?

Guidance: Yes. A controlled substances test must be administered any time employment has been terminated for more than 30 days and the exceptions under §382.301(c) were not met.

Question 4: Must all drivers who do not work for an extended period of time (such as layoffs over the winter or summer months) be pre-employment drug tested each season when they return to work?

Guidance: If the driver is considered to be an employee of the company during the extended (layoff) period, a pre-employment test would not be required so long as the driver has been included in the company’s random testing program during the layoff period. However, if the driver was not considered to be an employee of the company at any point during the layoff period, or was not covered by a program, or was not covered for more than 30 days, then a pre-employment test would be required.

For any non-regulated employees who are laid off for a period of time, we always recommend a pre-employment drug test when they are re-hired. You should describe this in your written policy as well.
Please let us know if you have questions.

For more information on employee drug testing for all industries, contact InOut Labs at www.inoutlabs.com or toll free at 833-723-7997.