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Colorado drug testing laws for employers
Colorado has no general workplace drug testing law, so private employers set their own rules. Adult-use and medical marijuana are legal, but the state constitution says employers do not have to allow marijuana at work and may keep policies against it. Colorado's off-duty conduct law protects only activity that is lawful under both state and federal law, so it does not protect marijuana users.
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The state law
- We found no Colorado law that sets general rules for private employers who drug test (no statute found).
- We found no Colorado workers' comp premium discount for drug-free workplace programs in state law (no statute found).
Testing applicants
- We found no Colorado law that limits applicant drug testing by private employers (no statute found).
Random testing
- We found no state law that limits random testing by private employers (no statute found).
Marijuana (recreational)
- The adult-use amendment does not require you to allow or accommodate marijuana at work and does not limit your policies restricting employee use (Colo. Const. art. XVIII, s. 16(6)(a)).
- The medical marijuana amendment does not require you to accommodate medical use at work (Colo. Const. art. XVIII, s. 14(10)(b)).
- Colorado bars firing workers for lawful off-duty activity, with exceptions for job-related needs and conflicts of interest (C.R.S. 24-34-402.5).
- The Colorado Supreme Court held that off-duty marijuana use is not 'lawful activity' under that law because it is illegal under federal law (Coats v. Dish Network, 2015 CO 44, noted under C.R.S. 24-34-402.5).
- We found no 2025 or 2026 change to the off-duty law; the 2026 code still shows 2007 as its last amendment (C.R.S. 24-34-402.5).
Also good to know
- A worker can be denied unemployment for having non-prescribed controlled substances, or alcohol at 0.04 or higher, in their system during work hours, shown by a test given under a law or your written drug policy at a licensed or certified lab (C.R.S. 8-73-108(5)(e)(IX.5)).
- Workers' comp wage benefits (not medical care) are cut 50% if the injury results from non-prescribed controlled substances or alcohol at 0.10 or higher, and the worker gets a split sample to retest at their own cost (C.R.S. 8-42-112.5).
Common questions
Is drug testing legal for employers in Colorado?
Colorado has no general workplace drug testing law, so private employers set their own rules. Adult-use and medical marijuana are legal, but the state constitution says employers do not have to allow marijuana at work and may keep policies against it. Colorado's off-duty conduct law protects only activity that is lawful under both state and federal law, so it does not protect marijuana users.
Can employers in Colorado test applicants before hiring?
We found no Colorado law that limits applicant drug testing by private employers (no statute found).
Is random drug testing allowed in Colorado?
We found no state law that limits random testing by private employers (no statute found).
Can a Colorado employer act on a positive marijuana test?
The adult-use amendment does not require you to allow or accommodate marijuana at work and does not limit your policies restricting employee use (Colo. Const. art. XVIII, s. 16(6)(a)).
Some rules for Colorado weren't confirmed from an official source. Check with the state before relying on this page.
Sources
- Colo. Const. art. XVIII, ss. 14 and 16 (OLLS 2026, official)
- C.R.S. 24-34-402.5 with annotations (OLLS 2026 Title 24, official)
- C.R.S. 8-73-108 and 8-42-112.5 (OLLS 2026 Title 8, official)
This page summarizes state law in plain words, with links to the law itself. It is not legal advice, and laws change: check the linked source, and talk to a lawyer about your own policy. Federal DOT testing rules are separate and override state limits for DOT-covered jobs. Checked October 2026.