DOT Drug-Test Panel and Cutoffs (49 CFR §40.85)

What a cutoff is, and what it is not

A cutoff concentration is the level at or above which a laboratory reports a result as positive. Below it, the laboratory reports negative — even where a trace amount was detected. That is the whole of it. A cutoff says nothing about impairment, nothing about when a substance was used, and nothing about how much was used Source 1DOT ODAPC49 CFR §40.85 — What are the drug test cutoff concentrations? — checked 17 Aug 2026.

Federal (DOT): Every analyte on the DOT panel has two cutoffs. The initial test is a fast screen across many samples; anything at or above the screening cutoff goes on to a confirmatory test by a more specific method, at a lower cutoff. Both numbers have to be met for a positive result to be reported Source 1DOT ODAPC49 CFR §40.85 — What are the drug test cutoff concentrations? — checked 17 Aug 2026Source 3eCFR49 CFR Part 40 — Procedures for Transportation Workplace Drug and Alcohol Testing Programs — checked 17 Aug 2026.

The DOT cutoff table

The table below reproduces §40.85 as currently in force. The DOT page and the eCFR text match exactly, and the section was last amended in May 2023 Source 1DOT ODAPC49 CFR §40.85 — What are the drug test cutoff concentrations? — checked 17 Aug 2026Source 2eCFR49 CFR §40.85 (current text) — checked 17 Aug 2026.

Why you will see different numbers elsewhere

Federal (HHS): There are two federal panels, not one. The DOT panel applies to safety-sensitive transportation employees. A separate panel, set out in the HHS Mandatory Guidelines, applies to federal civilian employees Source 4HHSMandatory Guidelines for Federal Workplace Drug Testing Programs — Authorized Testing Panels — checked 17 Aug 2026. They overlap heavily but they are not identical — the morphine confirmatory cutoff differs between them, and fentanyl is on the HHS panel and not on the DOT panel.

Federal (DOT): A rule to add fentanyl to the DOT panel was proposed in September 2025. It has not taken effect, so a DOT test today does not test for fentanyl Source 5Federal RegisterNPRM — Addition of Fentanyl to the DOT Testing Panel — checked 17 Aug 2026. If that rule is finalised, this page and the panel guide change the same week.

Employer policy: A non-DOT test your employer runs on its own account can use any panel and any cutoffs it likes. At-home tests also set their own levels, which is why a home test and a DOT laboratory test can disagree without either being faulty.