- Federal
- DOT · Federal
- Urine
- Oral fluid
What Is a Drug-Test Cutoff?
Short answer
A cutoff is the concentration at or above which a laboratory reports a result as positive. Below it, the result is reported negative — even if a trace was detected. Every analyte has two: a higher screening cutoff and a lower confirmatory one, and both must be met. Cutoffs are reporting thresholds set in advance, not measures of how much you used or whether you were impaired.
What matters most
- A cutoff is a reporting threshold, not a measurement of use or impairment.
- Each analyte has a screening cutoff and a lower confirmatory cutoff; both must be met.
- Below the cutoff is reported negative even when a trace amount is detected.
- The same drug has different cutoffs in different programmes and different specimens.
- At-home tests set their own levels, which is why they can disagree with a laboratory.
Jump to section
| Programme and specimen | Initial cutoff | Confirmatory cutoff |
|---|---|---|
| DOT urine (49 CFR §40.85) | 50 | 15 |
| HHS federal-agency urine | 50 | 15 |
| HHS federal-agency oral fluid | 2–4 | 2 |
What this means for you
Rules differ by state and employer. This section describes federal requirements. Your state law or your employer’s written policy may add rules on top of them.
When the answer changes

Dr. Matthew Nuesse
DOT Certified Medical Examiner
Dr. Matthew Nuesse is a DOT Certified Medical Examiner who reviews Exploro's drug testing guides for medical and procedural accuracy.
Common questions
What does a cutoff concentration actually mean?
It is the concentration at or above which a laboratory reports a result as positive. Below it, the result is reported negative — even if a trace amount was detected. Cutoffs are a reporting threshold, not a measure of impairment.
My home test and the laboratory disagreed. Which one is right?
The laboratory. A home test is a screening device set to its own cutoff, and the FDA describes consumer tests as qualitative — they suggest whether a substance may be present, not how much. Laboratory testing is the reliable way to confirm a result.
Does the DOT drug test include fentanyl?
No. The DOT panel covers marijuana, cocaine, amphetamines, PCP and a set of opioids that does not include fentanyl. A rule to add fentanyl was proposed in September 2025 but has not taken effect, so it is not tested for on a DOT test today.
Official sources
Every factual claim above is drawn from these sources. Each was opened and checked on the date shown. Where a rule differs between agencies, the source that governs is named in the text.
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DOT ODAPC · DOT §40.85
49 CFR §40.85 — What are the drug test cutoff concentrations?
View official source ↗ (opens in a new tab) -
eCFR · 49 CFR §40.85 (eCFR)
49 CFR §40.85 (current text)
View official source ↗ (opens in a new tab) -
HHS · HHS Mandatory Guidelines (2026)
Mandatory Guidelines for Federal Workplace Drug Testing Programs — Authorized Testing Panels
View official source ↗ (opens in a new tab) -
FDA · FDA — Home use tests
Drugs of Abuse Home Use Test
View official source ↗ (opens in a new tab) -
eCFR · 49 CFR Part 40 (eCFR)
49 CFR Part 40 — Procedures for Transportation Workplace Drug and Alcohol Testing Programs
View official source ↗ (opens in a new tab)