MRO PRACTICE QUESTIONS AND ANSWERS
(VERIFIED ANSWERS) STUDY GUIDE (LATEST
VERSION VERIFIED FOR ACCURACY) | LATEST!!
MRO PRACTICE QUESTIONS & ANSWERS
Medical Review Officer Certification Study Resource
2026–2027 Edition | Original Questions, Answer Key & Rationales
Instructions: Select the single best answer for each question. Review
the explanations after completing the practice test
SECTION A — REGULATIONS AND MRO RESPONSIBILITIES
Question 1
Which federal regulation provides the principal procedures for DOT-
regulated workplace drug testing?
A. 29 CFR Part 1910
B. 49 CFR Part 40
C. 42 CFR Part 2
D. 21 CFR Part 1300
Question 2
What is the primary role of a Medical Review Officer in the DOT drug-
testing process?
A. Decide employee discipline
B. Select the employer's drug-testing policy
C. Review laboratory results and evaluate relevant medical explanations
,under applicable procedures
D. Collect every specimen personally
Question 3
Who is responsible for conducting the medical interview and evaluating
relevant medical information during verification?
A. The MRO
B. The specimen collector
C. The employee's supervisor
D. The laboratory receptionist
Question 4
An employer disagrees with an MRO's verified result and asks the
laboratory to change it directly. Which statement is most accurate?
A. The employer can change any result by written request.
B. The laboratory receptionist can change the result.
C. The supervisor has final authority over the medical determination.
D. The MRO is the person authorized to change a verified result in the
circumstances permitted by Part 40.
Question 5
Which task is generally outside the MRO's function?
A. Reviewing relevant medical information
B. Deciding whether the employer should have ordered the test
C. Evaluating whether a prescription explains a finding
D. Conducting the required medical interview
Question 6
,An employee claims that a laboratory-positive result arose from a
legally prescribed medication. What should the MRO generally do?
A. Automatically verify the test negative
B. Allow the employee's supervisor to decide
C. Review the medical explanation and take reasonable and necessary
steps to authenticate supporting records
D. Ignore the medical history
Question 7
Why is the MRO's independent judgment important?
A. It helps ensure that verification follows medical evidence and
applicable regulations rather than pressure from interested parties.
B. It allows employers to bypass federal procedures.
C. It removes the need for laboratory testing.
D. It gives the MRO responsibility for all employment decisions.
Question 8
A donor disputes an event at the collection site, but the alleged event is
not reflected on the Custody and Control Form. What should the MRO
recognize?
A. Every dispute automatically cancels the test.
B. The employer must always decide the laboratory result.
C. The MRO must automatically verify positive.
D. Resolving factual disputes about collection-site events not reflected
on the CCF is generally outside the MRO's function.
Question 9
, Which statement best describes the relationship between DOT and HHS
testing guidance?
A. Every HHS document automatically overrides Part 40.
B. Each testing program must use the applicable framework; the 2025
SAMHSA MRO Guidance Manual does not govern DOT testing under
Part 40.
C. DOT and HHS procedures never differ.
D. MROs do not need to identify which program applies.
Question 10
An employee presents a state-issued medical marijuana card to explain
a DOT marijuana-positive result. Under current DOT guidance, what
should the MRO conclude?
A. The card automatically requires a negative verification.
B. The card replaces confirmatory laboratory testing.
C. State-authorized marijuana use does not constitute a legitimate
medical explanation for a DOT marijuana-positive result under current
guidance.
D. The employer must decide whether the card is sufficient.
SECTION B — LABORATORY RESULTS AND SPECIMEN VALIDITY
Question 11
What is the purpose of confirmatory drug testing?
A. To provide the required analytical confirmation of a qualifying initial
test finding using an authorized method
B. To diagnose substance-use disorder automatically
(VERIFIED ANSWERS) STUDY GUIDE (LATEST
VERSION VERIFIED FOR ACCURACY) | LATEST!!
MRO PRACTICE QUESTIONS & ANSWERS
Medical Review Officer Certification Study Resource
2026–2027 Edition | Original Questions, Answer Key & Rationales
Instructions: Select the single best answer for each question. Review
the explanations after completing the practice test
SECTION A — REGULATIONS AND MRO RESPONSIBILITIES
Question 1
Which federal regulation provides the principal procedures for DOT-
regulated workplace drug testing?
A. 29 CFR Part 1910
B. 49 CFR Part 40
C. 42 CFR Part 2
D. 21 CFR Part 1300
Question 2
What is the primary role of a Medical Review Officer in the DOT drug-
testing process?
A. Decide employee discipline
B. Select the employer's drug-testing policy
C. Review laboratory results and evaluate relevant medical explanations
,under applicable procedures
D. Collect every specimen personally
Question 3
Who is responsible for conducting the medical interview and evaluating
relevant medical information during verification?
A. The MRO
B. The specimen collector
C. The employee's supervisor
D. The laboratory receptionist
Question 4
An employer disagrees with an MRO's verified result and asks the
laboratory to change it directly. Which statement is most accurate?
A. The employer can change any result by written request.
B. The laboratory receptionist can change the result.
C. The supervisor has final authority over the medical determination.
D. The MRO is the person authorized to change a verified result in the
circumstances permitted by Part 40.
Question 5
Which task is generally outside the MRO's function?
A. Reviewing relevant medical information
B. Deciding whether the employer should have ordered the test
C. Evaluating whether a prescription explains a finding
D. Conducting the required medical interview
Question 6
,An employee claims that a laboratory-positive result arose from a
legally prescribed medication. What should the MRO generally do?
A. Automatically verify the test negative
B. Allow the employee's supervisor to decide
C. Review the medical explanation and take reasonable and necessary
steps to authenticate supporting records
D. Ignore the medical history
Question 7
Why is the MRO's independent judgment important?
A. It helps ensure that verification follows medical evidence and
applicable regulations rather than pressure from interested parties.
B. It allows employers to bypass federal procedures.
C. It removes the need for laboratory testing.
D. It gives the MRO responsibility for all employment decisions.
Question 8
A donor disputes an event at the collection site, but the alleged event is
not reflected on the Custody and Control Form. What should the MRO
recognize?
A. Every dispute automatically cancels the test.
B. The employer must always decide the laboratory result.
C. The MRO must automatically verify positive.
D. Resolving factual disputes about collection-site events not reflected
on the CCF is generally outside the MRO's function.
Question 9
, Which statement best describes the relationship between DOT and HHS
testing guidance?
A. Every HHS document automatically overrides Part 40.
B. Each testing program must use the applicable framework; the 2025
SAMHSA MRO Guidance Manual does not govern DOT testing under
Part 40.
C. DOT and HHS procedures never differ.
D. MROs do not need to identify which program applies.
Question 10
An employee presents a state-issued medical marijuana card to explain
a DOT marijuana-positive result. Under current DOT guidance, what
should the MRO conclude?
A. The card automatically requires a negative verification.
B. The card replaces confirmatory laboratory testing.
C. State-authorized marijuana use does not constitute a legitimate
medical explanation for a DOT marijuana-positive result under current
guidance.
D. The employer must decide whether the card is sufficient.
SECTION B — LABORATORY RESULTS AND SPECIMEN VALIDITY
Question 11
What is the purpose of confirmatory drug testing?
A. To provide the required analytical confirmation of a qualifying initial
test finding using an authorized method
B. To diagnose substance-use disorder automatically
