The Department of Transportation (DOT) drug test for pilots is a mandatory, highly regulated screening process governed by 49 CFR Part 40. Commercial pilots are subject to a "five-panel" drug screen that tests for Marijuana (THC), Cocaine, Amphetamines (including MDMA/Ecstasy), Opiates (including Heroin and Codeine), and Phencyclidine (PCP). Testing can occur in several scenarios: pre-employment, post-accident, "reasonable suspicion," and most commonly, unannounced random testing. Random tests act as a powerful deterrent and can happen at any time during a pilot's duty period. Alcohol testing is also conducted, usually via a breathalyzer, with a strict "bottle to throttle" rule—the FAA prohibits flying with a blood alcohol concentration of 0.04% or higher, though many airlines have even stricter "zero-tolerance" policies. In 2026, a single failed drug or alcohol test is often career-ending, as it leads to the immediate suspension or revocation of the pilot's medical certificate and license.