FMCSA does not require employers to conduct random testing on a specific monthly or quarterly schedule. The regulation requires the testing dates to be spread reasonably throughout the calendar year, and each random test must be unannounced.
In practice, employers should make selections and complete tests at least quarterly. Monthly selections may be more appropriate for employers with large pools, frequent turnover, seasonal operations, or drivers working in many locations. Quarterly testing can work for many smaller employers when the selections are properly administered and the required annual rates are achieved. FMCSA identifies quarterly selection and testing as a recommended approach rather than a separate regulatory mandate.
The key is to avoid a testing pattern that becomes predictable or leaves most testing until the end of the year.
What Do the 50% and 10% Random Testing Rates Mean?
The annual percentages apply to the employer’s average number of covered driver positions, not to a promise that a specific percentage of unique individuals will be tested.
For 2026, an FMCSA employer must conduct enough random tests to equal at least:
- 50% of its average number of covered driver positions for controlled-substances testing
- 10% of its average number of covered driver positions for alcohol testing
Example: Employer with 20 covered drivers
Assume an employer maintains an average of 20 covered driver positions throughout the year.
The annual minimums would generally be:
- 10 random drug tests: 20 × 50%
- 2 random alcohol tests: 20 × 10%
The employer could spread the drug tests across four quarterly selection periods, such as two or three tests per quarter. The actual distribution may vary because the selections must remain random.
The alcohol selections may be combined with some drug selections, but random alcohol tests must occur only while the driver is performing a safety-sensitive function, just before the driver performs one, or just after the driver stops performing one.
Does Every Driver Have to Be Tested Each Year?
No. The annual testing rate does not require the employer to test every driver.
Every covered driver must have an equal chance of selection during each selection period. Because each selection is a new random event:
- One driver may be selected more than once in the same year.
- A driver selected during the previous period must generally remain eligible for future selections.
- Another driver may not be selected at all during that year.
Employers should not remove a driver’s name from the pool simply because the driver was already tested. Doing so would prevent all covered drivers from having an equal chance of selection during subsequent periods.
A random program is not a rotating list in which each driver is tested once before anyone can be selected again.
Who Must Be Included in an FMCSA Random Testing Pool?
The pool should include drivers who are subject to FMCSA drug and alcohol testing requirements under Part 382. This generally includes CDL drivers who operate commercial motor vehicles requiring a commercial driver’s license in commerce.
Part-time, intermittent, seasonal, and backup drivers must be included when they remain employed and available to perform covered driving functions. FMCSA guidance confirms that part-time covered CDL drivers belong in the employer’s random pool.
Employers should not place non-DOT employees or drivers who are not subject to FMCSA testing into the DOT random pool. An employer may maintain a separate company-authority testing program, but it must remain clearly separate from the DOT program.
Drivers working for more than one employer
A driver who performs covered work for two employers generally must be included in each employer’s random testing program. Participation in one employer’s pool does not ordinarily satisfy the other employer’s responsibility.
Owner-operators
An owner-operator who employs only himself or herself as a driver cannot create a meaningful one-person random pool. Under FMCSA rules, a single-driver employer must participate in a consortium that includes at least two covered employees in the selection pool.
Through consortium and C/TPA program support, an owner-operator can be placed in an eligible random pool and have selections, notices, testing coordination, and records administered by a consortium/third-party administrator (C/TPA). The owner-operator remains responsible for meeting the applicable requirements.
Should Selections Be Monthly or Quarterly?
Both approaches may work, provided the program remains random, unannounced, reasonably spread throughout the year, and sufficient to meet the annual rates.
Quarterly selections
Quarterly selections are common for small and midsize employers. They can reduce administrative work while still distributing testing across the year.
A quarterly schedule might use selection periods such as:
- January through March
- April through June
- July through September
- October through December
A driver selected for a particular quarter should be tested during that selection period. FMCSA guidance indicates that completing the test in a later period can create a compliance problem, even though the completed test may still count toward the annual numerical minimum.
Monthly selections
Monthly selections may be helpful when an employer:
- Has a large or changing driver population
- Adds and removes drivers frequently
- Operates in many states
- Uses seasonal or intermittent drivers
- Wants to distribute testing more evenly
- Has experienced difficulty completing selected tests promptly
Monthly selection does not change the annual percentage. It divides the testing activity into more frequent and generally smaller groups.
Which schedule is better?
There is no single schedule that is best for every employer. Quarterly testing may be adequate for a stable pool, while monthly testing may make administration easier for a large or fluctuating workforce.
The employer should choose a schedule it can administer consistently without creating predictable testing dates.
How Quickly Must a Selected Driver Be Tested?
Once notified of a random selection, the driver must proceed immediately to the testing site. The employer should not give advance notice that allows the driver to delay the collection until a more convenient day.
The notice should occur when the employer can reasonably direct the driver to the collection site and complete the test promptly.
Random testing must remain unannounced. Practices that can undermine the program include:
- Telling drivers several days before the test
- Posting a schedule of planned random-testing dates
- Always testing during the same week of each quarter
- Allowing a selected driver to choose the testing date
- Delaying the test merely because the driver is busy
The employer should document the notification time, the person who notified the driver, and any circumstances that affected completion.
When Can Random Alcohol Testing Occur?
Random alcohol testing has a narrower timing rule than random drug testing.
An employer may conduct a random alcohol test only:
- While the driver is performing a safety-sensitive function
- Just before the driver will perform a safety-sensitive function
- Just after the driver stops performing a safety-sensitive function
An alcohol test conducted outside that window is not a valid FMCSA random alcohol test. FMCSA guidance has explained that an improper off-duty random alcohol test should be cancelled and documented.
Random drug testing does not have the same safety-sensitive timing limitation. A driver may be notified while off duty, provided the employer directs the driver appropriately and administers the test as a valid random test.
How Should Employers Handle a Changing Driver Count?
Employers should calculate their annual testing obligations using the average number of covered driver positions over the applicable selection periods.
This matters when the company:
- Starts operating partway through the year
- Hires or loses many drivers
- Merges with another company
- Splits operations
- Uses a seasonal workforce
- Moves drivers into or out of covered positions
FMCSA guidance provides a method based on the sum of covered driver counts for the selection periods divided by the total number of selection periods in a full year. The applicable drug or alcohol rate is then applied to that average. Any fractional test requirement should be handled conservatively so the employer reaches at least the required minimum.
Example: Employer beginning operations midyear
Assume a new employer begins covered operations in August and uses quarterly selections. It has:
- No covered drivers during the first two quarters
- 16 covered drivers during the third quarter
- 12 covered drivers during the fourth quarter
FMCSA’s published guidance applies the average over all four quarterly periods. The result requires four drug tests for that partial year, with testing distributed between the two operating quarters.
Employers should not wait until December and calculate the entire year using only the number of drivers employed at that moment.
What Happens When a Selected Driver Is Unavailable?
The answer depends on why the driver is unavailable and whether the driver remains employed in a covered position.
Examples may include a driver who is:
- On an extended leave
- Temporarily laid off
- Traveling outside the testing network
- No longer employed
- No longer performing covered functions
- Unavailable before the selection period ends
The employer or C/TPA should follow the random-program procedure and document the circumstances. An employer should not automatically substitute another handpicked driver. Any replacement selection should be made through the scientifically valid random-selection process.
A missed random test is not automatically a refusal. A refusal determination must be based on the specific conduct described in Part 40 and Part 382. Employers should review the driver’s notification, availability, instructions, actions, and supporting documentation before reaching that conclusion. Part 40 governs the testing procedures and refusal framework, while Part 382 establishes the FMCSA random-testing obligation.
Common Random-Testing Mistakes:
Waiting until the end of the year
Completing most or all random tests in November and December may fail the requirement to spread testing reasonably throughout the year, even if the employer reaches the numerical percentage.
Using predictable testing dates
Testing during the same week every quarter can reduce the deterrent value of the program. Random tests must be unannounced.
Treating the annual rate as a unique-driver quota
The percentage determines the minimum number of tests, not the number of different people who must be tested.
Removing previously selected drivers from the pool
A driver who was selected earlier generally remains eligible for selection again.
Including non-DOT employees in the DOT pool
DOT-covered and non-DOT employees should not be combined in the same random pool unless a specific DOT rule permits the combination. Non-DOT testing must remain separate and must not be represented as DOT testing.
Testing alcohol at the wrong time
A random alcohol test must be linked to the performance of a safety-sensitive function.
Failing to update the pool
The employer should promptly add newly eligible drivers and remove individuals who are no longer employed or no longer subject to the program.
Assuming a C/TPA holds all responsibility
A C/TPA may administer selections and coordinate collections, but the employer remains responsible for ensuring that its drivers are properly included, selected tests are completed, and the annual rates are met.
A Practical Random-Testing Checklist
Employers can use the following checklist to review their program:
- Confirm which employees are subject to FMCSA testing.
- Keep covered and non-covered employees in separate pools.
- Verify the current annual FMCSA testing rates.
- Choose monthly, quarterly, or another defensible selection schedule.
- Spread selections and tests reasonably throughout the year.
- Ensure every covered driver has an equal chance of selection.
- Keep previously selected drivers eligible for future selections.
- Notify selected drivers without advance warning.
- Direct drivers to proceed immediately once notified.
- Conduct alcohol tests only within the permitted safety-sensitive window.
- Update the pool as drivers are hired, transferred, terminated, or placed on extended leave.
- Monitor completed tests against the average number of driver positions.
- Document unavailable drivers and incomplete selections.
- Review C/TPA reports rather than assuming the required rate has been met.
- Retain records required by Part 382 and Part 40.
How a C/TPA Can Support Random Testing
A knowledgeable C/TPA can help employers:
- Maintain eligible random pools
- Perform scientifically valid selections
- Distribute selections across the year
- Coordinate collections across multiple locations
- Track completed and outstanding tests
- Monitor progress toward annual testing rates
- Document unavailable selections
- Maintain program records
- Support owner-operators and small employers
However, service-agent support does not transfer the employer’s ultimate compliance responsibility.
A WorkSAFE Service provides random-program administration, nationwide testing coordination, and consortium and C/TPA program support for employers with DOT-regulated and non-DOT workforces. A WorkSAFE Service also offers training to help employers and program administrators understand their responsibilities and manage testing procedures more consistently. Employers can contact A WorkSAFE Service to review their pool setup, selection schedule, testing coordination, or current program procedures.
Frequently Asked Questions:
Are quarterly random selections required?
No. FMCSA requires random tests to be unannounced and spread reasonably throughout the year. Official guidance recommends selections and testing at least quarterly, but employers may select more frequently.
Can the same driver be randomly selected twice?
Yes. Each covered driver must have an equal chance of selection during each selection period. A driver may be selected more than once in a year.
Can an employer complete all random tests in December?
That approach creates substantial compliance risk. Meeting the annual number does not excuse the separate requirement to spread testing reasonably throughout the calendar year.
Do part-time CDL drivers belong in the random pool?
Yes, when they remain covered by Part 382 and available to perform FMCSA-regulated driving.
Can random alcohol tests be conducted while drivers are off duty?
Not unless the test occurs just before or just after the driver performs a safety-sensitive function. Random alcohol testing is limited to the regulatory safety-sensitive window.
Does a driver who misses a random test automatically have a refusal?
No. The employer must examine the facts and apply the applicable refusal provision. A missed or incomplete test should not be labeled a refusal automatically.
Regulatory Sources
- 49 CFR § 382.305, FMCSA random-testing requirements.
- DOT 2026 random-testing rates.
- FMCSA official random-testing guidance.
- 49 CFR Part 40, governing DOT testing procedures.
