The FAA’s substance abuse policy sets a zero-tolerance standard for anyone whose job touches flight safety. You cannot fly within eight hours of drinking alcohol, cannot have a blood alcohol concentration of 0.04 or higher, and cannot test positive for marijuana, cocaine, opioids, PCP, or amphetamines. The rules reach past the cockpit into off-duty conduct: a DUI in your personal car must be reported to the FAA within 60 days, and common over-the-counter medications like Benadryl can ground you for days. Violations remove you from safety-sensitive duty until you complete a formal return-to-duty process, and a second positive drug test permanently bars you from the role you held.
The Eight-Hour Rule and Alcohol Limits
Under 14 CFR 91.17, you cannot act as a crewmember of a civil aircraft within eight hours of consuming any alcoholic beverage, while under the influence of alcohol, while using any drug that impairs your faculties contrary to safety, or with a blood alcohol concentration of 0.04 or higher.1eCFR. 14 CFR 91.17 – Alcohol or Drugs
Eight hours is a floor, not a ceiling. Alcohol clears at different rates in different people, and a heavy night can leave you above 0.04 well past the eight-hour mark.
For safety-sensitive employees under 14 CFR Part 120, a second threshold applies. A confirmed alcohol concentration of 0.04 or greater is a formal violation. A reading between 0.02 and 0.039 does not count as a violation but still pulls you off safety-sensitive duty immediately. You cannot go back until your concentration falls below 0.02 or your next scheduled duty period begins, whichever is later, and no sooner than eight hours after the test.2eCFR. 14 CFR Part 120 – Drug and Alcohol Testing Program
Prohibited Drugs and State Marijuana Laws
The FAA uses the Department of Transportation’s five-panel drug test, which screens for marijuana (THC), cocaine, opioids, phencyclidine (PCP), and amphetamines.3U.S. Department of Transportation. DOT 5 Panel Notice A positive result is a violation whether use was recreational, prescribed, or legal in your state.
State legalization changes nothing here. Even where recreational or medical marijuana is legal, the FAA prohibits performing safety-sensitive functions with marijuana or its metabolites in your system. A Medical Review Officer will not verify a test as negative based on state-legal use of any kind, and a verified positive marijuana result makes you unqualified to hold an FAA medical certificate.4Federal Aviation Administration. Q&As for Safety-Sensitive Employees The agency draws no line between medical and recreational marijuana for aviation.
Before a positive lab result becomes a violation, it goes to a Medical Review Officer, an independent physician who contacts you directly and gives you a chance to provide a legitimate medical explanation such as a valid prescription. If you hold a current prescription consistent with the Controlled Substances Act, the MRO may verify the test as negative. The MRO cannot accept explanations based on passive ingestion, hemp product consumption, or use of any Schedule I substance, marijuana included. You carry the burden of proof, and the MRO can give you up to five days to produce documentation like pharmacy records.5eCFR. 49 CFR Part 40 Subpart G – Medical Review Officers and the Verification Process
Who Has to Comply
The testing rules under 14 CFR Part 120 apply to anyone performing a safety-sensitive function, whether employed by an airline directly or working under contract at any tier, and whether full-time, part-time, temporary, or intermittent.6eCFR. 14 CFR Part 120 Subpart E – Drug Testing Program Requirements The covered functions are:
- Flight crewmembers and flight attendants
- Flight instructors
- Aircraft dispatchers
- Aircraft maintenance and preventive maintenance personnel
- Ground security coordinators
- Aviation screening personnel
- Air traffic controllers
- Operations control specialists
Contractors face the same obligations as direct employees and can either participate in the hiring airline’s program or register their own with the FAA’s Drug Abatement Division. One boundary worth noting: these testing requirements do not apply to safety-sensitive work performed by contract outside the United States.6eCFR. 14 CFR Part 120 Subpart E – Drug Testing Program Requirements
When You Can Be Tested
The FAA requires testing at five distinct points.
Pre-employment. No employer can place you in a safety-sensitive role until you pass a drug test with a verified negative result.
Random. Once employed, you enter a random selection pool that gives every covered employee an equal chance of selection each time. For 2026, DOT requires employers to randomly test at least 25% of their safety-sensitive workforce for drugs and 10% for alcohol annually.7U.S. Department of Transportation. 2026 DOT Random Testing Rates
Post-accident. If your performance contributed to an accident or cannot be ruled out as a contributing factor, the employer must test you as soon as possible and no later than 32 hours after the accident.
Reasonable cause. A supervisor who observes specific physical, behavioral, or performance indicators of probable drug use can order a test. At airlines with more than 50 safety-sensitive employees, two supervisors must concur and at least one must be trained in detecting symptoms of substance use. Smaller employers need only one trained supervisor.
Return-to-duty and follow-up. After a violation or refusal, you must pass a return-to-duty test before resuming work and then face at least six unannounced follow-up tests during your first 12 months back on duty, with the exact schedule set by a Substance Abuse Professional.6eCFR. 14 CFR Part 120 Subpart E – Drug Testing Program Requirements
What a Positive Test or Refusal Costs You
A first verified positive drug test removes you from safety-sensitive functions until you complete the full return-to-duty process. A second verified positive permanently bars you from the safety-sensitive duties you held before that second test. The same permanent disqualification applies if you used a prohibited drug during the actual performance of a safety-sensitive function.8eCFR. 14 CFR 120.111 – Administrative and Other Matters
Refusing a test carries essentially the same removal consequences as a positive result, and DOT’s definition of refusal is broad. You are considered to have refused if you fail to appear within a reasonable time after being directed to report, leave the testing site before collection is complete, fail to provide a specimen, refuse observation during a directly observed collection, cannot produce a sufficient specimen without an adequate medical explanation, decline an additional test the employer or collector directs, refuse a medical examination directed by the MRO, or fail to cooperate with any part of the process such as emptying your pockets or permitting an oral cavity inspection.9eCFR. 49 CFR 40.191 – What is a Refusal To Take a DOT Drug Test
A refusal does not by itself trigger the two-strikes rule that a verified positive does. It still requires immediate removal from safety-sensitive duties and completion of the return-to-duty process before you can work again.
That process runs through a DOT-qualified Substance Abuse Professional. The SAP conducts a clinical assessment, recommends education or treatment, and you must demonstrate successful compliance before returning to work. The SAP then conducts a follow-up evaluation to confirm compliance and sets the follow-up testing plan. You cannot shop for a second opinion; the regulations prohibit seeking a second SAP evaluation to get a different recommendation.10eCFR. 49 CFR Part 40 Subpart O – Substance Abuse Professionals and the Return-to-Duty Process
Substance Abuse and Dependence in Medical Certification
Separately from the testing program, 14 CFR Part 67 uses two definitions that determine whether you can hold a medical certificate.
Substance abuse is the broader category. You meet the FAA’s definition if, within the past two years, you used a substance in a physically hazardous situation and have at least one other instance of doing the same; you had a verified positive drug test, an alcohol test result of 0.04 or greater, or refused a DOT-required test; or the Federal Air Surgeon determines your substance use makes you unable to safely exercise your pilot privileges. The two-year clock runs from the most recent qualifying event.11eCFR. 14 CFR 67.107 – Mental
Substance dependence is a clinical diagnosis marked by increased tolerance, withdrawal symptoms, impaired control over use, or continued use despite damage to health or daily functioning. The regulation covers alcohol, opioids, stimulants like cocaine and amphetamines, cannabis, hallucinogens, sedatives, inhalants, and other psychoactive chemicals. Tobacco and caffeine are explicitly excluded. Returning to certification after a dependence finding requires established clinical evidence of recovery, including total abstinence for at least two years, satisfactory to the Federal Air Surgeon.11eCFR. 14 CFR 67.107 – Mental
Prescription and Over-the-Counter Medications
The rules stretch well beyond illegal drugs. Many common medications, prescription and OTC, are incompatible with flying. The FAA does not “approve” specific OTC medications, and FDA safety for general use does not mean cockpit safety.12Federal Aviation Administration. Over-the-Counter (OTC) Medications Reference Guide
The FAA maintains a “Do Not Fly” list of medication categories, which includes sedating antihistamines like diphenhydramine (Benadryl) and chlorpheniramine, anti-anxiety medications such as alprazolam and lorazepam, muscle relaxants like carisoprodol and cyclobenzaprine, narcotic and some non-narcotic pain medications including oxycodone, hydrocodone, and tramadol, all sleep aids (prescription and OTC), certain dietary supplements such as kava, kratom, and valerian, and pre-procedure sedation drugs.13Federal Aviation Administration. FAA Guide for Aviation Medical Examiners – DNI/DNF Tables
The general rule beyond the list is simple: if the label warns about drowsiness or advises caution when driving or operating machinery, do not fly while taking it.
Wait Times After Your Last Dose
Stopping the medication does not immediately clear you to fly. The FAA requires a wait of at least five dosing intervals after the last dose:
- Medication dosed every 4–6 hours: wait at least 30 hours
- Medication dosed every 8 hours: wait at least 40 hours
- Medication dosed every 12 hours: wait at least 60 hours
Some sedating antihistamines take longer because of their half-life. Diphenhydramine (Benadryl) and doxylamine (Unisom) require a 60-hour wait, and chlorpheniramine and clemastine require a full five days.12Federal Aviation Administration. Over-the-Counter (OTC) Medications Reference Guide For any new medication, FAA guidance is to wait at least 48 hours and to have experienced no side effects before flying.
Reporting a DUI or License Action
Your obligations reach beyond the airport. Under 14 CFR 61.15, you must report any alcohol- or drug-related motor vehicle action to the FAA within 60 days, even when the incident had nothing to do with aviation and happened in your personal car on your own time.14eCFR. 14 CFR 61.15 – Offenses Involving Alcohol or Drugs
A reportable “motor vehicle action” covers three categories of events occurring after November 29, 1990: a conviction for operating a motor vehicle while intoxicated, impaired, or under the influence of alcohol or a drug; the cancellation, suspension, or revocation of your driver’s license for the same type of cause; or the denial of a driver’s license application for the same reason. An administrative license suspension triggered by refusing a breathalyzer at a traffic stop counts. You do not need a criminal conviction for the reporting obligation to kick in.
A second motor vehicle action within three years of a previous one, unless both come from the same incident, is grounds for denial of any certificate application for up to one year, or outright suspension or revocation of your existing certificates and ratings. Missing the 60-day filing window is treated as a separate compliance violation and can independently result in suspension or revocation of all your FAA certificates, regardless of how the underlying case turns out.14eCFR. 14 CFR 61.15 – Offenses Involving Alcohol or Drugs
Getting Back to Flight Status Through HIMS
A substance-related disqualification does not have to be the end of a flying career. The Human Intervention Motivation Study (HIMS) program provides a structured path back to medical certification for pilots diagnosed with substance dependence or abuse. The core requirement is non-negotiable: permanent abstinence from all mind- and mood-altering substances for the rest of your flying career.15Federal Aviation Administration. HIMS AME Step Down Plan
Before entering the program, the FAA requires separate evaluations by a board-certified HIMS-trained psychiatrist and a neuropsychologist on the FAA’s approved provider list. Both produce detailed reports covering your substance use history, mental health status, cognitive testing, and an explicit opinion on aviation safety.16Federal Aviation Administration. Specifications for Psychiatric and Neuropsychological Evaluations for Substance Abuse/Dependence
Once in the program, you’ll see a HIMS-trained AME on a regular schedule, undergo evaluations by a HIMS psychiatrist or addiction specialist, participate in peer addiction support groups, complete peer pilot assessments, and submit to random testing that may include portable alcohol breath monitors with facial recognition. Progression through the program’s phases depends on your compliance, evaluator findings, and FAA review.15Federal Aviation Administration. HIMS AME Step Down Plan