This is one of the most-asked questions we get at National Standard Trucking School, and we give everyone the same direct answer: yes, drug testing is a non-negotiable part of becoming and remaining a commercial driver. It's not just a school policy — it's a federal requirement enforced by the FMCSA and the DOT. If you're considering CDL training, you need to understand how drug testing works at every stage of your career.
Pre-Employment Drug Testing
Before you start driving for any carrier, you'll take a pre-employment drug test. This is a DOT-regulated urine test conducted at a certified lab. It screens for marijuana (including THC from legal recreational use in Washington — federal law still classifies it as a controlled substance), cocaine, amphetamines, opioids, and PCP. There is no exception for states where marijuana is legal recreationally. This is federal law and it applies to every CDL holder in every state. Carriers will not hire you without a negative pre-employment test.
Testing During CDL Training
At NSTS, we make drug testing expectations clear from day one. Students need to be prepared to pass a drug test at any point during training. Showing up to training under the influence of any substance is grounds for immediate dismissal — we're putting you behind the wheel of an 80,000-pound vehicle on public roads. This isn't about judgment. It's about safety for you, our instructors, and everyone else on the highway.
Random and Post-Accident Testing
Once you're hired as a commercial driver, the DOT requires your employer to participate in a random drug and alcohol testing program. Each year, a percentage of the company's driver pool is randomly selected for testing — and you can be pulled for a test at any time during your shift. You'll also be tested after any DOT-reportable accident (fatality, injury requiring medical transport, or vehicle towed from the scene). Refusing a test is treated the same as a positive result.
What Happens If You Test Positive
A positive drug test triggers a process regulated by the DOT. You're immediately removed from safety-sensitive duties — meaning you can't drive commercially. Your positive result is recorded in the FMCSA Drug & Alcohol Clearinghouse, a national database that all carriers check before hiring. To return to driving, you must complete a Substance Abuse Professional (SAP) evaluation, follow the SAP's treatment recommendations (which can take months), pass a return-to-duty test, and then submit to follow-up testing for at least 12 months. A Clearinghouse record follows you for five years.
The Bottom Line
If you use marijuana — even legally in Washington — you need to stop well before you start CDL training. THC can be detectable in urine for 30 days or more depending on frequency of use. If you're taking prescription medications, bring documentation from your doctor to your DOT physical. Some prescriptions are compatible with commercial driving and some aren't. We'd rather have this conversation with you upfront than see you invest thousands in training and lose your career over a test you knew was coming. Call NSTS at (253) 210-0505 if you have questions.
