Clinical drug screens test for THC. Recreational legality in your state, a medical card, or "just CBD" usually won't excuse a positive result for clinical placement. Here's what the federal record says as of September 2026.
What changed in 2026
- An April 28, 2026 federal rule moved FDA-approved marijuana drug products and marijuana products covered by a state medical license into Schedule III. (source)
- The same day, DEA set a new hearing on rescheduling marijuana generally, starting June 29, 2026. (source) We found no final rule rescheduling marijuana generally as of September 2026, so non-medical marijuana remains Schedule I.
Medical cards still don't clear a positive test
The DOT drug-testing office's guidance, updated May 15, 2026, says state-dispensed marijuana is still not an FDA-approved drug even after rescheduling, and medical marijuana cards don't count as a legitimate medical explanation. (source) Student drug screens for clinicals aren't regulated by the Department of Transportation, but schools and reviewing doctors often follow the same federal procedures. Washington State University's policy, for example, cites the federal MRO guidance manual.
CBD can cause a positive THC test
- DOT: CBD labels could understate the THC in a product, CBD use isn't a legitimate medical explanation, and it could lead to a positive result. (source)
- FDA: many products tested did not contain the CBD levels they claimed, and some may contain THC. (source)
- The federal hemp definition is changing to count total THC, effective November 12, 2026. (source)
What programs say
- University of Arizona nursing prohibits marijuana, including medical marijuana. (source)
- Washington State University follows federal law despite Washington's legalization; students who test positive for THC after using CBD go through the positive-screen process. (source)
Reviewed by a Medical Review Officer? See why the MRO called.
Sources
- Federal Register, 91 FR 22714 (Apr. 28, 2026), Schedule III final rule
- Federal Register, 91 FR 22777 (Apr. 28, 2026), hearing notice
- DOT ODAPC Part 40 Q&A, 40.137 (updated May 15, 2026)
- DOT ODAPC CBD Notice
- FDA consumer update on cannabis and CBD products
- Congressional Research Service, IF13136
- University of Arizona nursing substance screening policy
- WSU College of Nursing drug screening policy
General information from public federal documents and published school policies as of September 2026, not medical or legal advice. Your program and clinical sites set the rules that apply to you.
Frequently asked questions
Does a medical marijuana card excuse a positive drug test for clinicals?
Usually not. Federal DOT guidance says medical cards aren't a legitimate medical explanation, and programs such as the University of Arizona's prohibit medical marijuana.
Can CBD make me fail a drug test?
It can. DOT warns CBD labels may understate THC, and FDA found many products didn't match their labels.
Is marijuana still federally illegal in 2026?
An April 2026 rule moved FDA-approved and state-licensed medical marijuana products to Schedule III. Marijuana generally remains Schedule I while a separate rescheduling hearing is pending.
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