DOT Alternate Selection Rules for Workplace Drug Testing - What Employers Need to Know

A random DOT drug test does not become flexible just because the selected employee is out for the day. That detail matters because using an alternate incorrectly can create compliance problems for the employer, even when the employee’s test result still stands.

On a recent Reliant on Compliance Minute, I focused on a situation that comes up more often than it should: an employee is tested as an alternate because the primary person is absent when the collector arrives onsite. Maybe the primary employee has a doctor’s appointment. Maybe they called in sick. Maybe they are on vacation for a few days.

Under DOT and FMCSA guidance, that is not enough reason to move to an alternate if the originally selected employee will return during the testing window.

Random testing periods should be managed across the full window, not just the collection day. For the record: Planned testing dates are ALWAYS confidential!

The issue with using an alternate for a short absence

In a recent SAP case, an individual reported that they had been tested as an alternate because the primary employee was out for a doctor’s appointment on the day that on-site testing was conducted. In this case, the original random selection had been made at the beginning of the quarter. The alternates, based on the documentation provided, were selected only two days before the onsite collection.

That creates a serious concern.

If the employer knew that one of the primary employees would not be present on the day the collector came onsite, that does not automatically justify using an alternate. The key question is not whether the employee is present on collection day. The key question is whether the employee will be available during the designated testing period.

For many employers, that period may be a month or a quarter, depending on how the random program is structured. If the employee will return before the end of that period, the employer should make arrangements to test the originally selected employee within the testing window.

An alternate should not be used simply because testing the primary employee is inconvenient.

That includes situations such as:

• The employee is off on the day the collector comes onsite

• The employee is out sick for a short period

• The employee has a medical appointment

• The employee is on a brief vacation

• The employee is on a temporary schedule change

• The collector showed up when the employee was not working

  
  

Random testing requires both randomness and proper follow-through. Once a covered employee is selected, the employer should not bypass that person unless there is a valid reason recognized under DOT guidance.

A positive test result will still stand even if the test was ordered incorrectly

This point can be frustrating, but it is critical.

If an employer orders a DOT test improperly, that does not erase a verified positive result. Prior rulings have recognized that a positive result will still stand, even when the test should not have been ordered in that manner.

In the SAP case mentioned above, the individual may have been selected as an alternate in a way that did not follow DOT rules. That does not change the fact that the urine drug screen came back positive.

Those are two separate issues.

The employer may have a compliance problem because the alternate was used incorrectly. The employee will still have a DOT violation because of the positive result.

For the employee, that means the return-to-duty process will still apply. For the employer, it means the testing process should be reviewed and corrected so the same mistake does not happen again.

DOT compliance is not only about getting people tested. It is about testing the right people, at the right time, under the right authority.

When an alternate may be used under DOT and FMCSA guidance

An alternate may be used when the primary selected employee is legitimately unavailable for the entire selection period.

That is the key phrase: the entire selection period.

If the random testing period is a quarter, then the primary employee must be unavailable for that quarter. If the testing period is a month, then the primary employee must be unavailable for that month.

Valid reasons may include:

• Extended medical leave

• Long-term illness or injury

• Layoff

• Extended vacation that covers the entire testing window

• The employee has left the company

• The employee is no longer in a DOT-covered safety-sensitive position for that entire period

  
  

These situations are different from a one-day absence. They prevent the employer from completing the test on the originally selected employee during the valid window.

In that case, the employer may use an alternate if the alternate was properly selected as part of the random selection process.

A valid alternate should come from the same controlled selection process.

What does not count as legitimate unavailability?

Short-term absence does not normally justify moving to an alternate. DOT random testing programs are built around a testing window for a reason. Employers are expected to manage the process across that full period.

A primary employee does not become unavailable just because they are not standing in front of the collector at that moment.

For example, assume an employee is selected at the beginning of a quarter. The collector comes onsite in the second month of the quarter, but the employee is at a doctor’s appointment that day. If the employee will return to work later that week, the employer should not simply call in an alternate.

The correct approach is to keep the primary selection active and complete the test when the employee is available, as long as that occurs during the selection period.

The same principle applies if the employee is out sick for a few days. A short illness may delay the test, but it does not usually make the employee unavailable for the entire period.

Employers should be careful not to let convenience drive the decision. Onsite collections are useful, but the collector’s schedule does not override DOT selection rules.

Alternates should be selected at the time of the original draw

When alternates are used, they should be part of the original random selection process. Best practice is for the DER or the company’s C/TPA to select alternates at the time of the original random draw.

That matters because alternates must come from the same scientifically valid random process as the primary selections. They should not be chosen later based on who is available, who is nearby, or who can be tested easily.

If alternates are selected days or weeks after the original draw, it raises questions about whether the selection was truly random. It can also make the program look reactive instead of controlled.

A clean process usually includes:

• The full random pool used for the draw

• The date the draw was conducted

• The testing period covered by the draw

• The primary selections

• The alternates selected during the same draw

• Documentation showing why an alternate was used

• Notes confirming that the primary employee was unavailable for the full period

  
  

This is where good records protect the employer. If a DOT audit or investigation asks why an alternate was tested, the file should answer that question clearly.

A simple note saying “primary was off that day” is not enough.

What the DER should document before using an alternate

The Designated Employer Representative has a key role in keeping the process compliant. Before using an alternate, the DER should confirm and document that the primary employee cannot be tested during the applicable window.

A strong documentation record may include:

• The primary employee’s status

• The reason the employee is unavailable

• The expected return date, if known

• Whether the unavailability covers the entire testing period

• The date the alternate was selected

• Confirmation that the alternate came from the same random draw process

• The date the alternate was notified and tested

  
  

The goal is not to create paperwork for its own sake. The goal is to show that the employer made a compliant decision based on the rules, not on convenience.

If the employee is only unavailable temporarily, the DER should keep the original selection active. The employer should then test that person when they return, as long as the testing period has not closed.

What to do when a selected employee is gone longer than expected

Sometimes an employer does not know at first whether an employee will return before the testing period ends. A short medical leave may become long-term. A temporary absence may stretch beyond the quarter.

In that case, the employer should track the dates carefully. If it becomes clear that the employee will not be available for the entire selection period, the employer may move to a properly selected alternate.

If the employee will return later, but not before the completion date of the next draw period, the situation may need a different compliance step. In many cases, the employee should be removed from the random testing list while they are not performing safety-sensitive duties. When they return, the employer should handle the return according to DOT requirements.

That may include a new Clearinghouse query, if required, and a pre-employment urine drug screen before the person resumes DOT-covered safety-sensitive functions.

The details can vary based on the employee’s status and the applicable DOT agency rules, so the employer should review the facts carefully. The safest practice is to avoid leaving inactive employees in the random pool when they are not actually eligible or available for testing.

Employee status and availability affect how random testing selections should be handled.

Why this matters for employers

Mistakes with alternates can create several problems.

The first is regulatory exposure. If an employer uses alternates for short absences, the random testing program may not meet DOT requirements. That can become an issue during an audit or after a crash investigation.

The second is fairness. Random testing must give each covered employee an equal chance of selection. If alternates are pulled in because they are present on collection day, the program may start testing the most available people instead of the randomly selected people.

The third is confusion after a positive result. An employee may challenge the test by arguing that they should never have been tested as an alternate. That challenge may not overturn the positive, but it can still expose weaknesses in the employer’s process.

For Workplace Drug Testing, process matters as much as outcome. A compliant program should be able to show how selections were made, why alternates were used, and whether each tested employee was handled under the correct DOT authority.

A practical way to handle random selections

Employers can prevent many alternate selection problems by using a clear standard process.

Start with the random draw. The DER or C/TPA should identify primary selections and any alternates at the same time. The draw should cover a defined period, such as a month or quarter.

Next, the DER should review the primary selections. If a primary employee is active and expected to be available during the testing period, that person remains the selection. Do not replace them because of a short absence.

If a primary employee is unavailable for the entire period, confirm the reason. Document it. Then use the next properly selected alternate.

After that, complete testing within the testing window. Avoid waiting until the last possible day whenever possible, because late scheduling leaves less room to handle absences correctly.

A simple workflow may look like this:

1. Conduct the random draw for the period.

2. Identify primary selections and alternates during the same draw.

3. Confirm whether each primary selection is available during the testing window.

4. Keep short-term absences assigned to the original selection.

5. Use an alternate only when the primary is unavailable for the full period.

6. Document the reason before testing the alternate.

7. Keep records with the random testing file.

   
   

This gives the DER a consistent path to follow. It also helps prevent rushed decisions when a collector is onsite and someone is missing.

Common employer mistakes to avoid

Alternate testing problems often come from good intentions. Employers want to complete testing. They want to meet their annual random testing rates. They want to avoid paying for another collector visit.

Those concerns are real, but they do not change the rules.

Avoid these common mistakes:

• Selecting alternates after learning who will be absent

• Replacing a primary employee because they are off for one day

• Treating onsite collection day as the whole testing window

• Failing to document why the alternate was used

• Keeping long-inactive employees in the random pool without review

• Assuming a testing error will erase a positive result

• Allowing supervisors to pick replacement employees informally

  
  

The strongest programs remove guesswork. The DER knows the policy. The C/TPA follows the draw process. Supervisors understand that “not here today” is not the same as “unavailable for the whole period.”

A correct random testing process supports valid collection steps.

The bottom line for DOT alternate selections

An alternate is not a backup employee to use whenever the primary person is absent. An alternate is a properly selected replacement used only when the primary selected employee is legitimately unavailable for the entire selection period.

If the primary employee is off, sick, or at an appointment on the day the collector arrives, that alone does not justify substitution. If the employee will return before the testing window closes, the employer should test the original selection.

At the same time, an incorrectly ordered test does not automatically disappear. A verified positive result may still carry DOT consequences, including the SAP and return-to-duty process.

The best protection is a clean process: select alternates during the original draw, use them only for valid reasons, document the decision, and keep the focus on the full testing window rather than the convenience of the collection day. DOT compliance works best when every selection can be explained without hesitation.

Partnering with a reputable C/TPA with experienced, knowledgeable staff is one way to ease the burden of your DOT and Workplace drug program compliance. Please reach out to Reliant Workplace Solutions for further information.