The Department of Transportation uses a 5-panel drug test. Despite the name suggesting only five substances, this panel actually screens for a broad list of specific drugs within five categories: marijuana (THC), cocaine, amphetamines, opioids, and phencyclidine (PCP). The testing is governed by federal regulation 49 CFR Part 40 and must be performed at laboratories certified by the Department of Health and Human Services.
The Five Drug Categories and What’s Inside Each
The “5-panel” label refers to five drug classes, but the actual number of individual substances tested is much higher. Here’s the full breakdown:
- Marijuana: THC metabolites
- Cocaine: Benzoylecgonine (cocaine’s primary metabolite)
- Amphetamines: Amphetamine, methamphetamine, MDMA (ecstasy), and MDA
- Opioids: Codeine, morphine, heroin (detected as 6-AM), hydrocodone, hydromorphone, oxycodone, and oxymorphone
- Phencyclidine: PCP
The opioid category is notably expansive. It covers not just traditional opiates like codeine and morphine but also commonly prescribed painkillers like hydrocodone (Vicodin) and oxycodone (OxyContin/Percocet). If you have a legitimate prescription for one of these medications, the Medical Review Officer will ask you about it during the verification process before finalizing a positive result.
The amphetamine category also catches some people off guard. Beyond street-level methamphetamine, it includes MDMA and MDA, both associated with ecstasy and molly. Prescription amphetamines like Adderall would also trigger this portion of the screen.
Cutoff Levels for Each Substance
DOT drug tests use a two-step process. An initial screening test catches anything above a set threshold. If that comes back positive, a second confirmatory test uses a more precise method and often a lower cutoff to eliminate false positives. All values are measured in nanograms per milliliter (ng/mL).
- Marijuana (THC): 50 ng/mL initial screen, 15 ng/mL confirmatory
- Cocaine: 150 ng/mL initial, 100 ng/mL confirmatory
- Codeine/Morphine: 2,000 ng/mL for both stages
- Hydrocodone/Hydromorphone: 300 ng/mL initial, 100 ng/mL confirmatory
- Oxycodone/Oxymorphone: 100 ng/mL for both stages
- Heroin (6-AM): 10 ng/mL for both stages
- Amphetamine/Methamphetamine: 500 ng/mL initial, 250 ng/mL confirmatory
- MDMA/MDA: 500 ng/mL initial, 250 ng/mL confirmatory
- PCP: 25 ng/mL for both stages
Notice the wide variation. The codeine and morphine threshold is set relatively high at 2,000 ng/mL, which helps prevent a poppy seed bagel from triggering a positive. Heroin’s marker, on the other hand, has an extremely low cutoff of just 10 ng/mL because 6-AM is uniquely produced by heroin metabolism and doesn’t come from food or medications.
How the Sample Is Collected
All DOT drug tests currently use urine specimens collected under a split-specimen protocol. The collector (not the employee) pours at least 30 mL of urine into the primary bottle and at least 15 mL into a second bottle. Both bottles are sealed with tamper-evident seals, dated, and initialed by the employee. Any leftover urine is discarded. The second bottle exists as a backup: if the primary specimen tests positive, you have the right to request that the split specimen be tested at a different certified laboratory.
Oral fluid (saliva) testing is on the horizon. The DOT published a final rule in November 2024 laying the groundwork for oral fluid testing, but it cannot be used in practice until HHS certifies at least one oral fluid testing laboratory. That hasn’t happened yet, so urine remains the only accepted specimen type for DOT tests.
What Happens If You Test Positive
A positive lab result doesn’t automatically go to your employer. It first goes to a Medical Review Officer (MRO), a licensed physician trained in substance abuse testing. The MRO reviews the lab paperwork for errors, then contacts you directly for a verification interview, either by phone or in person.
During that interview, you can present a legitimate medical explanation, such as a valid prescription for oxycodone or amphetamine-based ADHD medication. If the MRO accepts the explanation, the result is reported as negative. If there’s no valid explanation, the MRO verifies the result as positive and reports it to your employer’s designated representative.
The MRO (or their staff) must make at least three attempts over a 24-hour period to reach you using the phone numbers on your testing form. If they can’t reach you, they contact your employer’s representative, who then instructs you to call the MRO. If more than 72 hours pass after that employer contact and you still haven’t responded, the MRO can finalize the result without your input. The absolute outer limit is 10 days from when the MRO received the lab result: after that, the positive is verified regardless of contact.
Who Has to Take This Test
The DOT 5-panel applies to safety-sensitive employees across several federal agencies. This includes commercial truck and bus drivers regulated by the Federal Motor Carrier Safety Administration, airline employees under the FAA, pipeline workers under PHMSA, railroad employees under the FRA, transit workers under the FTA, and maritime workers under the Coast Guard. The same 5-panel standard applies to all of them. Individual employers cannot substitute a different panel or add substances to the DOT test, though they can run a separate non-DOT test under their own company policy.
Testing can occur in six situations: pre-employment, random selection, reasonable suspicion, post-accident, return-to-duty after a violation, and follow-up testing. The substances, cutoffs, and collection procedures are identical in all six scenarios.