Official US Government Icon

Official websites use .gov
A .gov website belongs to an official government organization in the United States.

Secure Site Icon

Secure .gov websites use HTTPS
A lock ( ) or https:// means you’ve safely connected to the .gov website. Share sensitive information only on official, secure websites.

Drug Testing Laboratories


Drug testing laboratories certified by the Department of Health and Human Services receive urine specimens and test them to determine the presence of drugs. They also conduct validity testing to determine if the specimen has been adulterated or substituted.

A laboratory located in the U.S. is only permitted to participate in DOT drug testing only if it is certified by HHS under the National Laboratory Certification Program (NLCP) or in the case of a foreign laboratory, if it is approved for participation by the DOT with respect to Part 40.

As a reminder, only those laboratories identified under the HHS-Certified Laboratories list are permitted to participate in the DOT drug testing program. HHS-Certified Instrumented Initial Testing Facilities are not authorized for use in the DOT drug testing program.

Applicable Regulations

A laboratory participating in DOT drug testing must comply with the requirements in 49 CFR Part 40, as well as, all applicable HHS requirements. While it is important for the laboratory to be familiar with all aspects of 49 CFR Part 40, the laboratory should pay particular attention to the following:


Association/Industry Links

A red and white checkered hot-air balloon is rising up toward the right, above a complex maze below. A slogan to the right of the balloon says, “Preventing Substance Abuse Begins with Knowledge.”