21 CFR 1308.II.
Schedule I, an amphetamine, a narcotic, or any other habit-forming drug.
Exception: A driver may use such a substance or drug, if the substance or
drug is prescribed by a licensed medical practitioner who is familiar with
the driver's medical history and assigned duties; and has advised the
driver that the prescribed substance or drug will not adversely affect the
driver's ability to safely operate a commercial motor vehicle.
This exception does not apply to methadone. The intent of the medical
certification process is to medically evaluate a driver to ensure that the
driver has no medical condition which interferes with the safe performance
of driving tasks on a public road. If a driver uses a Schedule I drug or
other substance, an amphetamine, a narcotic, or any other habit-forming
drug, it may be cause for the driver to be found medically unqualified.
Motor carriers are encouraged to obtain a practitioner's written statement
about the effects on transportation safety of the use of a particular drug.
A test for controlled substances is not required as part of this biennial
certification process. The FMCSA or the driver's employer should be
contacted directly for information on controlled substances and alcohol
testing under Part 382 of the FMCSRs.
The term "uses" is designed to encompass instances of prohibited drug
use determined by a physician through established medical means. This
may or may not involve body fluid testing. If body fluid testing takes place,
positive test results should be confirmed by a second test of greater
specificity. The term "habit-forming" is intended to include any drug or
medication generally recognized as capable of becoming habitual, and
which may impair the user's ability to operate a commercial motor vehicle
The driver is medically unqualified for the duration of the prohibited
drug(s) use and until a second examination shows the driver is free from
the prohibited drug(s) use. Recertification may involve a substance abuse
evaluation, the successful completion of a drug rehabilitation program, and
a negative drug test result. Additionally, given that the certification period
is normally two years, the examiner has the option to certify for a period of
less than 2 years if this examiner determines more frequent monitoring is
(See Conference on Neurological Disorders and Commercial Drivers and
Conference on Psychiatric Disorders and Commercial