Drug testing laws in hiring: what federal law allows and what states restrict

Federal law does not ban pre-employment drug testing, and most employers may still test candidates before making an offer. What has changed since legalization spread is narrower: a growing list of states now restrict what an employer may do with a positive marijuana result, rather than restricting the test itself. Safety-sensitive and federally regulated positions are carved out of nearly every one of these state laws, and marijuana's move to Schedule III in 2026 did not change federal transportation testing rules at all.

The federal baseline: testing itself is generally allowed

Two federal points anchor everything below.

• The ADA does not treat a test for illegal drug use as a medical examination. The EEOC's guidance on preemployment medical inquiries confirms that testing for current illegal drug use falls outside the ADA's restrictions on pre-offer medical exams, so an employer may generally test at any stage of hiring. A positive result can still lead into ADA territory if the employer then asks about lawful prescriptions or other medical explanations, which is where the process needs care.
• Marijuana remains federally illegal for regulated safety-sensitive testing regardless of state law or its 2026 rescheduling. The Department of Transportation has stated that moving marijuana to Schedule III did not rewrite its testing rules, and that a laboratory-confirmed positive result cannot be verified as negative based on a state medical marijuana card, dispensary receipt or physician recommendation. Pre-employment, random, post-accident, reasonable-suspicion and return-to-duty testing remain mandatory for DOT-regulated positions such as commercial drivers.

States that restrict acting on a marijuana test result

These states do not generally ban the test. They limit what the employer may do once the result comes back positive for marijuana, usually by barring an adverse hiring decision based solely on a positive result or on off-duty use, with an exception for safety-sensitive and federally regulated roles.

This is not a complete list of every state addressing cannabis and hiring; several additional states have narrower medical-marijuana-card protections or apply only to current employees rather than applicants, distinctions we did not attempt to summarize in one line here. Check the specific state statute for a state not listed above rather than assuming no protection exists.

What is allowed in every state on this list

• Testing for on-the-job impairment. None of the statutes above stop an employer from acting on evidence that someone is impaired at work.
• Barring on-duty use or use of employer property, including company vehicles, even off the clock.
• Testing safety-sensitive and DOT-regulated roles under the ordinary federal framework, and taking action on a positive result there, cannabis included.
• Testing for drugs other than cannabis under a standard drug-free workplace policy; these statutes are written around cannabis specifically, not around drug testing generally.
• Maintaining a drug-free workplace policy as a condition of certain state contracts, workers' compensation premium discount programs, or federal grant requirements, which several states preserve explicitly.

Procedural details that trip up an otherwise compliant policy

• Advance notice. Connecticut requires the applicant be told at the time of application that testing is part of the process. Build notice into your job posting or application flow rather than surprising a candidate at the final stage.
• Confirmatory or retest rights. Nevada gives an applicant tested within the first 30 days of employment the right to pay for and submit a second test to rebut the first, which the employer must accept and give appropriate consideration.
• "Solely" is doing real work in several statutes. New Jersey and Connecticut both frame their restriction around a positive test being the sole basis for the decision, which means documented, independent evidence of impairment, not the test result itself, is what an employer needs on file before acting.
• Metabolite tests versus impairment tests are legally different things. California's and Washington's statutes specifically target tests that detect only non-psychoactive metabolites, which can reflect use from weeks earlier, not current impairment. A newer test designed to measure active impairment is treated differently under some of these laws; confirm with counsel before assuming either kind is safe.

Where the ADA still applies

A drug test for illegal use is not itself a medical exam, but the process around it can still raise ADA issues. If a positive result leads you to ask a candidate why, and the honest answer is a prescribed medication for a disability, you have crossed from testing for illegal drug use into a disability-related inquiry, which does carry ADA obligations. Keep the follow-up narrow: confirm whether a lawful, prescribed explanation exists for the result, document it, and do not use the conversation to probe the underlying condition. For the broader set of questions federal and state law restrict during hiring, see illegal interview questions and ADA accommodations in interviews.

A worked example: two candidates, one policy

This is an invented example to show why the record you keep matters as much as the policy. Suppose a staffing agency in New Jersey extends conditional offers to two warehouse-forklift candidates, Dana and Priya, and both test positive for THC metabolites only.

• Dana has no other flags: no incident, no reasonable-suspicion referral, nothing beyond the metabolite result. Under New Jersey's statute, that result alone cannot be the sole basis for withdrawing the offer, because forklift operation was not designated by the agency in advance as one of the roles exempted for safety reasons, and the agency has no independent, objective evidence of impairment.
• Priya's file also shows a documented reasonable-suspicion referral from a site supervisor who observed slurred speech and unsteady movement during the working interview, recorded the same day, before the test was ordered. That independent, contemporaneous observation is the kind of objective basis the statute requires alongside the test result.

The difference is not the test result, which was identical. It is whether the file contains anything beyond the metabolite screen. An agency that only ever documents the test itself will struggle to defend a decision in a state that requires more.

A checklist for a pre-employment testing policy

1. Identify whether the role is safety-sensitive or DOT-regulated. Those roles follow the federal framework regardless of state cannabis protections.
2. Check the state where the work is performed against the table above, not the state where your company is headquartered.
3. Give notice of testing in the posting or application, not only at the offer stage, in states that require it.
4. Separate metabolite screening from impairment evidence in your records, so a positive result is never the only documented basis for a hiring decision in a state that requires more.
5. Build in a confirmatory retest path where state law requires one, such as Nevada's 30-day window.
6. Train whoever handles a positive result to ask only whether a lawful explanation exists, and to stop there, keeping the process out of ADA disability-inquiry territory.
7. Revisit the policy at least yearly. This is one of the areas of employment law most likely to have changed since your policy was last written.

For the separate question of what a background check vendor may and may not do under federal law, see the FCRA background check process. For how criminal history questions interact with the hiring timeline, see ban-the-box laws.