Random Drug Testing: Everything You Need to Know

Stephanie Colestock
January 11, 2024
6 min read

Random drug testing can help employers ensure they meet compliance requirements and maintain a safe work environment, especially in high-risk and safety-sensitive industries such as manufacturing, transportation, construction, and more. Certain roles may even require that employees submit to random drug testing to meet legal requirements. 

In this article, we’ll cover why random drug testing is important for employers, when workplace drug testing should be conducted, why employers may conduct random drug tests, and the reasons that compliance is so important.

Start drug testing with Checkr today

What is random drug testing?

Random drug testing in the workplace occurs when an employer orders a drug and/or alcohol screening for an eligible employee without prior warning. These unannounced screenings can enable employers and federal agencies to ensure workplace compliance and safety, while also helping deter drug and alcohol use in the workplace. 

Employees are typically selected for a random drug test by a computer program or other method of randomization, and tests are conducted at unpredictable intervals throughout the year. Employees may be subject to more frequent random screening if they’ve previously failed a drug test, recently completed a rehabilitation program, or are in safety-sensitive roles.

Keep in mind that employment drug testing is not always random; it can also be triggered by an event, such as accepting an offer of employment. Reasonable suspicion of substance abuse or a traffic-related incident, such as a crash or DUI, may also be grounds for drug testing in some jurisdictions and industries. 

There are two common categories that random drug testing can fall into: Department of Transportation (DOT) random tests and non-DOT random tests. In some cases, employees may be subject to both. Depending on company policy and state and local laws, tests might be conducted on-site or at a certified laboratory. 

Let’s take a closer look at each type of screening.

DOT drug testing

DOT random drug tests are administered to employees who fall under the Department of Transportation (DOT) regulation umbrella, such as commercial driver’s license (CDL) drivers, to detect drug or alcohol use on the job. Depending on the employer, specific DOT drug testing requirements are set forth by entities such as the: 

Each of these DOT agencies sets their own random testing rates each year. These rates specify the minimum percentage of employees that must be tested for drugs and/or alcohol from a random pool each year, without prior notice, in order to meet federal guidelines.

Here are the random testing thresholds for 2023:

In addition to random drug testing, DOT requirements also include a pre-employment drug test, as well as testing following an accident or eligible traffic violation.

Non-DOT random drug tests are those administered to employees in industries that are not regulated by the U.S. Department of Transportation. These drug tests may be administered in accordance with the employer’s own background check policies as well as state and local drug testing regulations, even if they are not subject to DOT guidelines. Non-DOT random drug testing often allows for more flexibility in terms of testing methods, and many employers may choose to conduct cost-effective onsite tests (such as oral fluid tests) or use lab-based tests similar to those required by the DOT.

Why are random drug testing programs important?

Random drug testing programs are important as they play an integral role in helping employers mitigate risk, promote safe working environments, and deter alcohol or drug use among employees while at work. This type of testing can help employers meet compliance requirements within their industry, especially if they operate in a high-risk environment or if they are subject to DOT regulations. This could include (but is not limited to) bus or truck drivers, heavy machinery operators, mechanics, corrections and safety officers, or those who handle hazardous materials. 

By making these tests random, employers can fairly encourage compliance and safety throughout the course of employment. Since tests can be requested at any time and without prior notice, employees in the eligible testing pool may be more motivated to abstain from illicit drug and alcohol use.

In addition to random testing, some employees may be required to submit to drug testing as part of the pre-employment background check process. Testing can be triggered in response to a workplace-related incident or reasonable suspicion of substance abuse, as well, in accordance with state and local laws and company drug testing policies. 

What shows up on a random drug test?

Depending on the test, random drug screens may show the presence of alcohol, illicit drugs, or certain controlled substances in an employee’s system. These random drug tests are often conducted using a urine drug test, but may also involve providing an oral fluid, blood, or a hair follicle sample.

Non-DOT-regulated employers may choose which substances to test for and how to administer testing, while DOT drug tests look for specific substances and cannot be performed onsite. 

FMCSA guidelines require DOT random drug tests to screen for:

    • Marijuana

    • Cocaine

    • Opiates (including opium and codeine derivatives)

    • Amphetamines and methamphetamines

    • Phencyclidine (PCP) 

    • Blood alcohol levels (alcohol concentration of 0.02 or higher)

Marijuana testing is included in testing in all states since the drug is still considered illegal at the federal level. DOT testing regulations do not allow for marijuana use at any level or for any reason, regardless of local or state laws.

With that said, state and local laws in the US may regulate whether certain non-DOT employers are permitted to test for marijuana in random employee drug testing. States like New York, for instance, have prohibited most employers from testing for marijuana during or prior to employment, excluding certain limited circumstances. 

Outside of regulated testing requirements, DOT employees may also be subject to non-DOT company testing according to the employer’s guidelines.

Start drug testing with Checkr today

How do random drug tests work?

A random drug test begins when an employee is randomly selected for testing by a computer program, employer system, or even an unbiased third party. The employee is then notified of the selection either by a supervisor, HR team employee, or automatic notification from the organization’s random testing provider and given information on how and where to proceed so they can submit a sample for testing. In some cases, employees will be asked for a sample on-site, while at other times, they may need to visit a designated laboratory for testing. 

In order to be considered statistically random, drug tests must follow an objective selection methodology. Most employers use a computer-generated selection system for choosing random drug testing candidates to ensure that the process is fair and impartial. Random testing may be conducted at any time during employment as allowed by the employer’s written policies, DOT guidelines (if applicable), and state and local laws.

Random drug testing at work may require a sample of the employee’s oral fluid, blood, urine, or even hair follicles. Depending on the sample obtained and the testing criteria, these tests may be conducted in the workplace, in a designated testing center, or sent to a laboratory for analysis. Employees may be required to provide a sample within a specific period of time, often during the same workday that the employee is notified of test selection. 

To enable compliance and align with best practices, employers should consider sharing their random drug testing policy and receiving consent from employees in writing prior to conducting a test. This often occurs during the hiring or onboarding process. If you work with a consumer reporting agency, like Checkr, you are required to disclose intent to conduct a drug test and receive written consent from employees prior to ordering any screenings (even if the timing of the test will be random) to comply with the federal Fair Credit Reporting Act (FCRA).

Best practices for ensuring compliance in the workplace

To ensure compliance when conducting random drug tests in the workplace, employers may opt for a multi-faceted approach. This could include creating a drug testing policy, prioritizing clear employee communication, and following the strictest applicable legal requirements. Here are some tips for following the best practices regarding random drug testing.

Create a random drug testing policy

Each employer should outline their specific drug testing requirements and procedures as part of a standard workplace random drug testing policy and in accordance with Fair Credit Reporting Act (FCRA) guidelines. This way, all potential and current employees are aware of the expectations, company and regulatory requirements, and any repercussions for positive drug test results, so there is no confusion regarding the process. 

Follow federal, state, and local regulations

Depending on where the employer operates, the industry, and even the functions of each employee, employers may be subject to certain federal, state, and/or local regulations regarding drug testing. It’s imperative to understand which laws and guidelines apply to which employees, noting that in many cases, you may need to follow more than one standard.

Communicate clearly with employees

Employers should include drug testing information in the employee handbook, at minimum, and provide a copy to employees at the soonest opportunity. This ensures that all employees are made aware of and given access to the company’s random drug testing procedures and understand the repercussions of such a policy. 

If drug testing is also conducted as part of a pre-employment screening—along with things like education verification and a comprehensive background check—this should be made clear early in the job offer process. Employees should also provide written consent for this drug testing before it is conducted, and obtaining this consent may be mandatory for compliance with the FCRA if you work with a third-party background check provider to conduct testing.

Choose the right screenings for your industry

Some employees may be subject to more than one type of random drug screening, depending on the industry and employer guidelines. While employers can set their own workplace testing requirements according to state law, employees who are subject to DOT regulations will also need to follow the specific DOT testing guidelines. Working with a CRA, like Checkr, can simplify the drug testing requirement process and help support workplace compliance.

Start drug testing with Checkr today

Random drug testing laws and requirements

Different laws regulate random drug testing depending on the state, industry, and even specific substances being tested. It’s important for employers to understand the random drug testing laws in the jurisdictions in which they have employees, to ensure compliance with the federal, state and local requirements.

DOT regulations

DOT-regulated employees are required to submit to random drug testing over the course of their employment, according to federal guidelines. This can include CDL drivers and other employees that fall under the federal transportation umbrella. DOT random drug testing requirements can include alcohol, illicit drugs, and certain prescription medications.

Fair Credit Reporting Act (FCRA)

The FCRA is a federal law that requires employers working with a CRA to provide written disclosure to, and obtain written consent from, job candidates or employees before conducting a background check (such as drug testing). If the outcome of a background check results in an adverse action, employers should follow the adverse action process outlined in the FCRA to maintain compliance. 

Random drug testing by state

Random drug testing laws vary from state to state, and there is no federal regulation regarding random drug testing. In places like New York, for example, non-DOT employees may be subject to random drug testing but tests may not be used to detect marijuana. Other states allow random employment drug testing, but only if the employee is notified of the policies beforehand and in writing. 

The following states may either permit random drug testing for all lawful uses, limit random drug testing to certain industries or positions, or prohibit random drug testing. If a state is not listed here, it may not regulate random drug testing. Local laws can also regulate this type of employment drug testing.

States where random testing is generally permitted

    • Alabama: Random and/or other lawful drug testing of employees is permitted. See law.

    • Alaska: Random drug testing is allowed as long as the methods and requirements are disclosed to employees beforehand and in writing. See law.

    • Arizona: Random drug testing is allowed as long as the methods and requirements are disclosed to employees beforehand and in writing. See law.

    • Florida: Random drug testing is allowed as long as the methods and requirements are disclosed to employees beforehand and in writing. See law.

    • Georgia: Random drug testing is allowed as long as the methods and requirements are disclosed to employees at least 60 days beforehand and in writing. See law.

    • Hawaii: Random drug testing is allowed as long as the employee is given a written list of substances covered by the test as well as a statement on prescription and over-the-counter medications that may trigger a positive test result. See law.

    • Idaho: Random drug testing is allowed as long as the employer’s policy on methods, requirements and repercussions is provided in writing beforehand. See law.

    • Iowa: Random drug testing is allowed as long as the employer’s policy has been provided to all eligible employees in writing. See law.

    • Kentucky: Random drug testing is allowed as long as it is conducted using a statistically valid and unannounced method, and that the employee is given a written copy of the workplace drug-free and testing policies. See law.

    • Louisiana: Employers who conduct random drug testing for specific substances must do so through certified laboratories, especially if the employee would be subject to negative employment consequences following a positive test result. See law.

    • Maryland: Random drug testing is allowed as long as specimens are processed through a certified laboratory, and if the employer provides the employee with the name and address of that lab upon request. See law.

    • Maine: Random drug testing of current employees is allowed, but drug-testing employers with more than 50 full-time employees are also required to establish an employee assistance program. See law.

    • Mississippi: Random drug testing is allowed as long as it is conducted using a neutral selection basis and the employee has received a written copy of the company’s drug testing policy at least 30 days prior. See law.

    • Montana: Random drug testing is allowed as long as a written copy of the employer’s policy has been provided to all eligible employees at least 30 days prior, and the testing is conducted by a third-party with an established and scientific selection process. See law.

    • Nebraska: Employers with at least six employees are allowed to conduct random drug testing, but can only use the results to fire or discipline employees if certain testing requirements are met. See law.

    • North Carolina: Random drug testing is allowed if performed by an approved laboratory. Positive test results must be confirmed by a second test of the same sample. See law.

    • Ohio: Random drug testing of 15% of the workforce is allowed by select employers who have enrolled in the state’s Advanced level drug-free safety program, and who provide employees with a written copy of the program’s policies within 90 days of the program’s start. See law.

    • Oregon: Random drug testing is allowed, but only through registered and approved laboratories. See law.

    • South Carolina: Random drug testing is allowed as long as all employees are notified of the program and its policies either at the time of hiring or when the program is implemented. See law.

    • Tennessee: Random drug testing is allowed as long as the process is considered lawful. See law.

    • Utah: Random drug testing of employees is allowed as long as upper-level employees and management is also subject to testing, and if a written copy of the company’s drug testing policy has been provided to all employees. See law.

    • West Virginia: Random drug testing is allowed as long as the employer’s written policy has been distributed to all employees and made available to prospective employees. See law.

    • Wyoming: Random drug testing is allowed as long as it is conducted on 20% of staff annually. The company must also implement a written policy that is distributed to all eligible employees, and notify employees at least 60 days before any new drug testing programs are introduced. See law.

States where random testing is permitted in special cases

    • Connecticut: Employers are allowed to conduct random drug screenings if the employee has a high-risk occupation or voluntarily participates in certain employee assistance programs. See law.

    • Minnesota: Random drug testing is only allowed for professional athletes or employees in safety-sensitive positions. See law.

    • Oklahoma: Random drug testing is allowed for select categories of employees (including peace officers, public hospital employees, those working with inmates or anyone authorized to carry a firearm), and only if a written copy of the employer’s policy is provided at least 10 days prior to the start of the program. See law.

States where random testing is not permitted

    • Vermont: Random drug testing of employees is not allowed unless required by federal law. See law.

FAQs on random drug testing

How often are random drug tests done?

While there is no universal guideline for how often random drug tests should be conducted, the FMCSA recommends testing employees quarterly or more frequently. The allowed—or in some cases, required—frequency of random drug screening depends on whether the employee is subject to DOT regulations, the company’s testing policy, and any applicable state or local laws. In addition to random testing, drug screens may also be conducted as part of a pre-employment testing process or in response to a workplace incident such as an injury, accident, or violation.

What happens if an employee fails a random drug test?

The repercussions of failed or refused random employee drug testing depend on the employer and any specific disciplinary action policies in place. For non-DOT employees, company policy may dictate that the employee be placed on a leave of absence until a confirmation test can be conducted, or that a drug testing refusal results in automatic termination (if allowed by state and local law).

DOT-regulated employees who fail or refuse drug or alcohol testing must be immediately removed from any safety-sensitive tasks or positions. The return-to-duty process involves working with a DOT-qualified substance abuse professional, contingent on the specific circumstances. 

Are random drug tests really random?

Typically, yes. Employers use objective selection technology, like computer programs, to ensure random drug tests are truly random and do not target specific employees. Federal employment discrimination regulations included in Title VII of the Civil Rights Act of 1964 make it unlawful for employers to select employees or volunteers for random drug tests based on protected characteristics.

Are random drug tests legal?

Random drug testing is not prohibited in most states. When it comes to certain states or DOT-regulated employees, screening can be a requirement. Each state has its own laws surrounding random employee drug testing, so it’s important for employers to note those limitations when designing their own drug testing policies. 

What is the difference between random drug testing and reasonable suspicion testing?

Random drug testing is conducted without warning, pattern, or selectivity, while reasonable suspicion testing is conducted when an employer has reason to believe that an employee may be under the influence of drugs or alcohol. Reasonable suspicion testing is limited in most states and often requires the belief that testing an employee will result in evidence of current impairment. 

Get started on your random drug testing program with Checkr

Random drug testing* helps employers of all sizes maintain compliance with industry regulations while protecting both workplace and public safety. Checkr offers a wide range of pre-employment and post-hire background check options that help you perform faster, safer screenings at any scale. Employers partner with us to speed up and streamline regular or random drug testing, DOT drug testing, criminal record checks, motor vehicle report checks, and many more background screenings. With 100+ ATS integrations available, adding Checkr to your existing business operations is simple. 

Get started with Checkr now.

*Random drug testing is currently in limited early availability release at Checkr. To learn more or participate in early access, please sign up here.


The resources provided here are for educational purposes only and do not constitute legal advice. We advise you to consult your own counsel if you have legal questions related to your specific practices and compliance with applicable laws.

About the author

Stephanie Colestock is a professional writer who covers a variety of small business and financial topics. For Checkr.com, her work is aimed at helping both employers and job candidates navigate the hiring and employment process in the most informed and effective way.

Keep reading


Ready to get started?