When can an employer require a drug test?
It depends on the industry, jurisdiction, policy, contract, and reason for testing. Programs may include pre-employment, random, reasonable-suspicion, post-accident, return-to-duty, and follow-up testing. State and local law can restrict some categories.
Are all workplace tests governed by DOT rules?
No. DOT rules apply to covered safety-sensitive transportation testing. A non-DOT employer should not label its test “DOT” or apply Part 40 selectively. Some employers run separate DOT and company-authority programs.
Can prescribed medication cause discipline?
A medical review officer may verify a legitimate explanation under the applicable program. Disability and safety rules can still permit a separate, individualized assessment in some circumstances. Employees should use the authorized confidential review channel rather than disclose diagnoses broadly.
Does a positive result prove on-the-job impairment?
Usually not. It may establish that an analyte was detected above a cutoff. Workplace policy may prohibit use or a positive result without requiring proof of current impairment, but those are different conclusions.
What happens after a nonnegative screen?
Consequential programs typically require laboratory confirmation and may include medical review before a final verified result is reported. Ask whether the result is a screen, confirmed laboratory finding, or final MRO verification.
Can an employee request a retest?
Some programs provide split-specimen testing or another review procedure, often with a short deadline. Preserve the notice and request the written policy immediately.
What about cannabis?
Federal contractors, DOT-regulated workers, and other programs may follow federal rules. State and local protections for lawful off-duty use, medical cannabis, or pre-employment testing vary. No single rule applies nationwide.
Who should receive the result?
Access should be limited to authorized people under the applicable law and policy. Results and medical explanations should not be circulated casually. Ask for the privacy and retention policy.
What records should I keep?
Keep the policy, notice, consent, collection receipt, laboratory and MRO communications, prescriptions, deadlines, and appeal requests. Contemporaneous records are especially important after post-accident or reasonable-suspicion testing.
Related: Workplace Drug Testing, Employee Rights, and the complete FAQ.