In workplace safety and occupational health, Medical Review Officers (MROs) play a crucial role in overseeing drug testing programs. As licensed physicians, they are responsible for interpreting and verifying drug test results, ensuring compliance with federal regulations, and maintaining integrity in drug-free workplace programs. Obtaining an MRO certification is essential for physicians who want to specialize in substance abuse testing and compliance. This guide provides a comprehensive overview of MRO roles, responsibilities, certification requirements, and career opportunities.

MRO Exam at a Glance

What changed for MRO in 2026

• Oct 25, 2026: Exam fee changed to $525 per exam (previously $525 per exam (initial or recertification); training course extra).^[1]
• Oct 25, 2026: Exam fee (Recertification exam + self-study CME) changed to $695 (previously $695 (recert exam + 25-hour self-study CME)).^[1]
• Oct 25, 2026: Number of questions (Recertification (online)) changed to 100 multiple-choice questions (onsite paper: 110) (previously 100 multiple-choice questions (onsite paper version: 110)).^[1]
• Oct 25, 2026: Time limit (Initial Certification) changed to Up to 3 hours, one sitting (previously 3 hours, one sitting).^[1]
• Oct 25, 2026: Passing score changed to Psychometrically set minimum passing level, based on total correct (previously Psychometrically set minimum passing level; based on total correct).^[1]
• Oct 25, 2026: Score release (Onsite paper exam) changed to Within 4–5 weeks by email (previously 4–5 weeks after the exam).^[1]
• Oct 25, 2026: Eligibility (Initial Certification) changed to MD/DO with valid license + MROCC-approved MRO training in past 12 months (previously Licensed MD/DO + MROCC-approved MRO training (ACOEM, AOCOPM or AAMRO) within past 12 months).^[1]

According to Medical Review Officer Certification Council, “Scores are determined and reported based upon the total number of items answered correctly. There is no penalty for guessing.”^[1]

Worked examples: how to reason through MRO questions

These are practice questions written for this site, not questions from the real exam. Each explanation shows why the right answer is right and why the others are wrong.

Example 1

Question: How does risk management apply to daily practice in Federal Acquisition Regulations for Medical Review Officer professionals?

1. Through proactive identification of potential hazards and implementation of preventive measures
2. Only through responding to incidents after they occur
3. By avoiding high-risk situations entirely
4. Through annual safety audits exclusively

Answer: A. Through proactive identification of potential hazards and implementation of preventive measures

Explanation:

The correct answer is that risk management works through proactive identification of potential hazards and preventive measures. Waiting to respond only after incidents occur is wrong because it accepts the harm first and deals with it later. Avoiding high-risk situations entirely is wrong because many professional duties cannot be dropped, so the risk has to be managed rather than escaped. Relying on audits exclusively is wrong because a periodic check leaves long gaps in which hazards go unnoticed.

The rule to remember: good risk management is continuous and forward-looking. It combines routine hazard spotting, preventive steps and a response plan. Be wary of answer options containing words like only, entirely or exclusively, since they usually describe a single narrow tactic. Note that this question is framed around federal acquisition rules, which is not the core of MRO review work, so give more of your time to the drug testing sets.

Example 2

Question: Under HHS Mandatory Guidelines, which of the following is a required element of a laboratory's internal quality control program for immunoassay screening?

1. Running a minimum of 20 calibrators per batch
2. Including negative, positive, and cutoff calibrators in each analytical run
3. Testing each specimen in duplicate before reporting any result
4. Performing confirmatory GC-MS on all immunoassay negatives

Answer: B. Including negative, positive, and cutoff calibrators in each analytical run

Explanation:

The correct answer is that each analytical run includes negative, positive and cutoff calibrators or controls. This lets the laboratory show that the screening assay can tell a true negative from a result at the decision point, and that it is working on that day. Running 20 calibrators per batch is wrong because it is an invented fixed count, not a guideline requirement. Testing every specimen in duplicate is wrong because duplicate testing is not what the quality control program requires before reporting. Confirmatory GC-MS on all immunoassay negatives is wrong because confirmation is aimed at presumptive positives, not at every negative.

The rule to remember: quality control is about proving each run works, using known materials at and around the cutoff, rather than repeating work on every specimen.

Example 3

Question: Which federal agency sets the guidelines for workplace drug testing?

1. OSHA
2. DEA
3. SAMHSA
4. NIH

Answer: C. SAMHSA

Explanation:

The correct answer is SAMHSA, the Substance Abuse and Mental Health Services Administration. It issues the standards and protocols that federal workplace drug testing programs follow, including how laboratories and specimens are handled. OSHA is wrong because it deals with workplace safety and health conditions, not the testing guidelines themselves. DEA is wrong because it enforces drug laws and controls scheduled substances, which is a different role. NIH is wrong because it is a medical research agency and does not set workplace testing rules.

The rule to remember: match the agency to its function. SAMHSA sets the testing guidelines, and DOT applies them to the workers it regulates. When two agencies seem plausible, ask which one actually writes the technical standard rather than enforcing, researching or inspecting.

How to use these practice tests

Start with the official page at mrocc.org. Note whether you are sitting initial certification or recertification, since the question count and time limit differ. Then check which delivery mode you will use, because an open-book online exam and a closed-book paper exam call for different preparation.

Next, work through the practice sets that match MRO daily work: Drug Testing Procedures, Donor Interview and Verification, Review and Interpretation, Confidentiality and Ethics and Regulatory Compliance. Answer without looking, then read each explanation, including for questions you got right, and write down the rule behind each miss.

Some other sets on this page, such as contract types, cost and pricing, source selection and small business programs, cover federal acquisition topics. They are not clearly tied to the MROCC exam, so treat them as optional and use them only if your course material points there.

Our questions are written by us and are not real exam questions, so use them to find weak areas, not to predict your score. Turn each weak area into a reading task from your approved MRO training course and manual. Near test day, do a timed run in a single sitting, matching your exam format.

Key Takeaways

Free MRO Practice Test Online

• Medical Review Officers (MROs) play a crucial role in verifying workplace drug test results and ensuring compliance with federal and state laws.

• To become a certified MRO, a licensed physician must complete training and pass a certification exam.

• MROs help employers maintain safe work environments by preventing substance abuse-related risks.

• Certified MROs are in demand in occupational health, transportation, and government agencies.

What Is a Medical Review Officer?

A Medical Review Officer (MRO) is a licensed physician responsible for analyzing, verifying, and reporting drug test results in workplace and clinical settings. MROs ensure that test results comply with federal and state regulations, protecting both employers and employees from false positives or inaccurate assessments.

• Maintains accuracy and integrity in drug testing programs

• Ensures legal compliance with Department of Transportation (DOT) and Occupational Safety and Health Administration (OSHA) regulations

• Protects employee rights by verifying valid prescriptions or legitimate medical explanations for positive test results

• Prevents workplace substance abuse-related risks and enhances safety

Medical Review Officer Near Me

If you need an MRO for workplace drug testing, legal cases, or compliance requirements, you can find certified professionals through:

• Occupational health clinics

• Government agencies and compliance organizations

• Online directories of MRO-certified professionals

• Employers implementing drug-free workplace programs

• Healthcare organizations conducting pre-employment drug testing

• Government agencies ensuring compliance with federal safety regulations

• Transportation and logistics companies following DOT drug testing guidelines

Medical Review Officer Definition

The term Medical Review Officer (MRO) refers to a licensed physician who has undergone specialized training in drug test verification and compliance procedures.

An MRO acts as an independent and objective reviewer in drug testing programs. Their responsibilities include:

• Reviewing and verifying drug test results

• Investigating medical explanations for positive tests

• Ensuring compliance with federal drug testing regulations

• Protecting confidentiality and employee rights

• Providing expert testimony in legal or workplace disputes

How to Become a Medical Review Officer

To become a Certified Medical Review Officer, you must:

• Be a licensed physician (M.D. or D.O.)

• Complete an MRO certification training program

• Pass an MRO certification exam

• Obtain a medical degree (M.D. or D.O.) and a valid medical license

• Complete a Medical Review Officer training course offered by accredited organizations

• Pass the MRO certification exam to demonstrate expertise in drug testing regulations and review procedures

• Register with a national MRO certifying organization to maintain professional credentials

• Stay updated on regulatory changes through continuing education programs

What Does a Medical Review Officer Do?

MROs perform essential tasks that support drug-free workplace policies and federal compliance regulations. Their key responsibilities include:

• Analyzing laboratory drug test results to confirm accuracy

• Contacting employees with positive test results to discuss medical explanations

• Determining whether a drug test result is valid, invalid, or requires further investigation

• Reporting verified results to employers, government agencies, or healthcare providers

• Providing expert opinions in legal cases involving drug testing disputes

• Transportation and logistics (airlines, trucking, railroads)

• Healthcare and pharmaceutical companies

• Federal and state government agencies

• Private corporations with drug-free workplace policies

Conclusion

Becoming a Medical Review Officer (MRO) is an excellent career path for physicians specializing in occupational health and substance abuse testing. With federal regulations requiring drug testing in various industries, certified MROs play a vital role in workplace safety and compliance.

Obtaining an MRO certification enhances career opportunities, credibility, and expertise in drug testing review and legal compliance. Whether working for corporations, healthcare institutions, or government agencies, an MRO ensures the accuracy, fairness, and confidentiality of drug test results.

For physicians interested in expanding their careers in occupational health and regulatory compliance, becoming a certified MRO is a valuable and rewarding path.

Sources & last verified

1. Medical Review Officer Certification Council — number of questions, time limit, passing score, exam fee (official source). “Consists of 110 multiple choice questions” Verified Oct 25, 2026.
2. Medical Review Officer Certification Council — retake policy (official source). “The retest policy permits the examination to be taken two additional times for free within a 12 month period from the date of registration for…” Verified Oct 25, 2026.

How we verify: editorial & fact-checking policy. Report an error: contact us.