1
MRO Practice Exam Actual Exam 2026/2027
– Complete Exam-Style Questions with
Detailed Rationales | 100% Verified | Pass
Guaranteed – A+ Graded
[SECTION 1: DOT 49 CFR Part 40 Regulations — Questions 1-20]
Q1: Under 49 CFR Part 40, what is the responsibility of the Medical Review Officer (MRO)
when a laboratory reports a positive test result?
A. To immediately contact law enforcement.
B. To forward the result directly to the employee's supervisor.
C. To verify the result with the donor to determine if there is a legitimate medical explanation.
D. To destroy the specimen to maintain privacy.
Correct Answer: C
Rationale: The MRO's primary role is to act as an independent gatekeeper to ensure the accuracy
of the drug test result. Before reporting a positive to the employer, the MRO must conduct a
medical interview with the donor to verify if there is a legitimate medical explanation, such as a
valid prescription. Contacting law enforcement (A) is not the MRO's role, and reporting to the
supervisor (B) must wait until verification is complete.
Q2: Which federal agency issues the mandatory guidelines for Federal Workplace Drug Testing
Programs that the MRO must follow in addition to DOT regulations?
A. Food and Drug Administration (FDA).
B. Occupational Safety and Health Administration (OSHA).
C. Substance Abuse and Mental Health Services Administration (SAMHSA).
D. Drug Enforcement Administration (DEA).
Correct Answer: C
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Rationale: SAMHSA is part of the U.S. Department of Health and Human Services (HHS) and
sets the scientific and technical standards (Mandatory Guidelines) for drug testing labs, which
MROs must utilize. The DOT (49 CFR Part 40) adopts these HHS guidelines for workplace
testing.
Q3: According to 49 CFR Part 40, what is the time frame within which an employee must
request a test of the split specimen after being notified of a verified positive, adulterated,
substituted, or invalid result?
A. 72 hours.
B. 24 hours.
C. 48 hours.
D. 7 days.
Correct Answer: A
Rationale: Under 40.161, the employee has the right to request that the split specimen be tested
within 72 hours of being notified of the verified result. The MRO must notify the employee of
this right. If the request is made outside this window, the MRO is not obligated to honor it.
Q4: What constitutes a "Refusal to Test" under DOT regulations regarding specimen
temperature?
A. The specimen temperature is exactly 98.6°F.
B. The specimen temperature is between 90°F and 100°F.
C. The specimen temperature is outside the range of 90°F – 100°F (32°C – 38°C) and the
employee cannot provide a legitimate medical explanation.
D. The specimen temperature is 100.1°F but the employee feels hot.
Correct Answer: C
Rationale: While 90°F–100°F is the acceptable range, a specimen outside this range is a validity
failure. However, to be classified as a refusal, the MRO must determine there is no legitimate
medical reason for the abnormal temperature (e.g., hyperthermia). If no explanation is provided,
the employee is deemed to have refused to test (40.191).
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Q5: Which of the following documents must the collector complete during a urine drug test
collection?
A. The Drug Testing Custody and Control Form (CCF) with 5 copies.
B. The employer’s internal payroll form.
C. The laboratory chain of custody worksheet.
D. The Medical Review Officer’s verification report.
Correct Answer: A
Rationale: The Federal Drug Testing Custody and Control Form (CCF) is the mandatory form
(Step 2 of the collection process) used to document the chain of custody. It consists of 5 copies
(lab, MRO, employer, employee, and collector copy). The other documents are not part of the
standard collection protocol.
Q6: Under Part 40, who is responsible for selecting the consortium or breath alcohol technician
(BAT) for a non-DOT covered employee?
A. The Medical Review Officer.
B. The Substance Abuse Professional (SAP).
C. The state government.
D. The employer.
Correct Answer: D
Rationale: Employers are responsible for implementing and maintaining their drug and alcohol
testing programs. They must select the service agents (consortia, collection sites, labs, BATs) that
meet DOT requirements, even if the employee is not DOT-covered (for company policy testing),
though specific DOT rules strictly apply only to safety-sensitive employees.
Q7: Which of the following is NOT a valid "medical explanation" for a specimen with a low
specific gravity (dilute) submitted by an employee?
A. The employee was drinking alcohol heavily the night before.
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B. The employee drank large quantities of water prior to the test.
C. The employee has a medical condition causing polyuria.
D. The employee was undergoing diuretic therapy under a physician's care.
Correct Answer: A
Rationale: Drinking alcohol is not a legitimate physiological reason for a dilute specimen in the
context of a medical explanation for a test validity failure; it might be an admission of recent
intoxication. Options B, C, and D relate to fluid intake or medical conditions affecting urine
concentration, which the MRO considers when evaluating a negative-dilute result.
Q8: What is the verification cutoff concentration for marijuana metabolites (THC-COOH) in a
urine specimen under HHS Mandatory Guidelines?
A. 50 ng/mL.
B. 15 ng/mL.
C. 100 ng/mL.
D. 20 ng/mL.
Correct Answer: B
Rationale: While the initial screening cutoff for marijuana is 50 ng/mL, the confirmation cutoff
using GC/MS or LC-MS/MS is 15 ng/mL. The MRO verifies the result at the confirmation level.
If the screening is positive but confirmation is below 15 ng/mL, it is reported as negative.
Q9: When a donor claims that a positive opioid test result is due to prescription medication, the
MRO must:
A. Ignore the claim and report the positive result.
B. Ask the donor to stop taking the medication.
C. Review the prescription details (name, dosage, prescribing doctor) to ensure it is consistent
with the positive result.
D. Contact the police to report the prescription drug use.
MRO Practice Exam Actual Exam 2026/2027
– Complete Exam-Style Questions with
Detailed Rationales | 100% Verified | Pass
Guaranteed – A+ Graded
[SECTION 1: DOT 49 CFR Part 40 Regulations — Questions 1-20]
Q1: Under 49 CFR Part 40, what is the responsibility of the Medical Review Officer (MRO)
when a laboratory reports a positive test result?
A. To immediately contact law enforcement.
B. To forward the result directly to the employee's supervisor.
C. To verify the result with the donor to determine if there is a legitimate medical explanation.
D. To destroy the specimen to maintain privacy.
Correct Answer: C
Rationale: The MRO's primary role is to act as an independent gatekeeper to ensure the accuracy
of the drug test result. Before reporting a positive to the employer, the MRO must conduct a
medical interview with the donor to verify if there is a legitimate medical explanation, such as a
valid prescription. Contacting law enforcement (A) is not the MRO's role, and reporting to the
supervisor (B) must wait until verification is complete.
Q2: Which federal agency issues the mandatory guidelines for Federal Workplace Drug Testing
Programs that the MRO must follow in addition to DOT regulations?
A. Food and Drug Administration (FDA).
B. Occupational Safety and Health Administration (OSHA).
C. Substance Abuse and Mental Health Services Administration (SAMHSA).
D. Drug Enforcement Administration (DEA).
Correct Answer: C
,2
Rationale: SAMHSA is part of the U.S. Department of Health and Human Services (HHS) and
sets the scientific and technical standards (Mandatory Guidelines) for drug testing labs, which
MROs must utilize. The DOT (49 CFR Part 40) adopts these HHS guidelines for workplace
testing.
Q3: According to 49 CFR Part 40, what is the time frame within which an employee must
request a test of the split specimen after being notified of a verified positive, adulterated,
substituted, or invalid result?
A. 72 hours.
B. 24 hours.
C. 48 hours.
D. 7 days.
Correct Answer: A
Rationale: Under 40.161, the employee has the right to request that the split specimen be tested
within 72 hours of being notified of the verified result. The MRO must notify the employee of
this right. If the request is made outside this window, the MRO is not obligated to honor it.
Q4: What constitutes a "Refusal to Test" under DOT regulations regarding specimen
temperature?
A. The specimen temperature is exactly 98.6°F.
B. The specimen temperature is between 90°F and 100°F.
C. The specimen temperature is outside the range of 90°F – 100°F (32°C – 38°C) and the
employee cannot provide a legitimate medical explanation.
D. The specimen temperature is 100.1°F but the employee feels hot.
Correct Answer: C
Rationale: While 90°F–100°F is the acceptable range, a specimen outside this range is a validity
failure. However, to be classified as a refusal, the MRO must determine there is no legitimate
medical reason for the abnormal temperature (e.g., hyperthermia). If no explanation is provided,
the employee is deemed to have refused to test (40.191).
,3
Q5: Which of the following documents must the collector complete during a urine drug test
collection?
A. The Drug Testing Custody and Control Form (CCF) with 5 copies.
B. The employer’s internal payroll form.
C. The laboratory chain of custody worksheet.
D. The Medical Review Officer’s verification report.
Correct Answer: A
Rationale: The Federal Drug Testing Custody and Control Form (CCF) is the mandatory form
(Step 2 of the collection process) used to document the chain of custody. It consists of 5 copies
(lab, MRO, employer, employee, and collector copy). The other documents are not part of the
standard collection protocol.
Q6: Under Part 40, who is responsible for selecting the consortium or breath alcohol technician
(BAT) for a non-DOT covered employee?
A. The Medical Review Officer.
B. The Substance Abuse Professional (SAP).
C. The state government.
D. The employer.
Correct Answer: D
Rationale: Employers are responsible for implementing and maintaining their drug and alcohol
testing programs. They must select the service agents (consortia, collection sites, labs, BATs) that
meet DOT requirements, even if the employee is not DOT-covered (for company policy testing),
though specific DOT rules strictly apply only to safety-sensitive employees.
Q7: Which of the following is NOT a valid "medical explanation" for a specimen with a low
specific gravity (dilute) submitted by an employee?
A. The employee was drinking alcohol heavily the night before.
, 4
B. The employee drank large quantities of water prior to the test.
C. The employee has a medical condition causing polyuria.
D. The employee was undergoing diuretic therapy under a physician's care.
Correct Answer: A
Rationale: Drinking alcohol is not a legitimate physiological reason for a dilute specimen in the
context of a medical explanation for a test validity failure; it might be an admission of recent
intoxication. Options B, C, and D relate to fluid intake or medical conditions affecting urine
concentration, which the MRO considers when evaluating a negative-dilute result.
Q8: What is the verification cutoff concentration for marijuana metabolites (THC-COOH) in a
urine specimen under HHS Mandatory Guidelines?
A. 50 ng/mL.
B. 15 ng/mL.
C. 100 ng/mL.
D. 20 ng/mL.
Correct Answer: B
Rationale: While the initial screening cutoff for marijuana is 50 ng/mL, the confirmation cutoff
using GC/MS or LC-MS/MS is 15 ng/mL. The MRO verifies the result at the confirmation level.
If the screening is positive but confirmation is below 15 ng/mL, it is reported as negative.
Q9: When a donor claims that a positive opioid test result is due to prescription medication, the
MRO must:
A. Ignore the claim and report the positive result.
B. Ask the donor to stop taking the medication.
C. Review the prescription details (name, dosage, prescribing doctor) to ensure it is consistent
with the positive result.
D. Contact the police to report the prescription drug use.
