What is an MRO?

What is an MRO?



A Medical Review Officer is an “impartial, licensed physician who analyses laboratory results from drug testing programs and provides medical explanations for specific drug test results”. Their purpose is to ensure the accuracy of the test results and give the donor an opportunity to explain why they may have positive results.


MROs can be independent contractors on an as-needed basis for companies or be under the jurisdiction of a Federal agency. As a necessary step in the drug testing process, it is important for employers, organizations, and agencies to have an MRO in mind before testing or ensure that the Third Party Agency who performs their test uses an accredited MRO.



Required Qualification for an MRO


A qualified MRO needs to adhere to HHS Mandatory Guidelines for Federal Workplace Drug Testing Programs if they are working within the U.S. Department of Transportation (DOT) regulated testing. In Canada, where there are no regulatory bodies presenting requirements for drug and alcohol testing, it has been accepted that MROs follow the same industry standard which has been set out within the U.S. drug and alcohol testing industry which is overseen by numerous regulatory bodies. To be certified as an MRO you must:

  • Be a licensed physician with a Doctorate in Medicine or Osteopathy,

  • Have expert knowledge in toxicology and pharmacology of illicit drugs and substances,

  • Successfully have been reviewed by an MRO certifying association and passed their exam

  • Professionally trained to:

    • The HHS Mandatory Guidelines for Federal Workplace Drug Testing Programs standard,

    • Understand the procedures for the collection of federal agency specimens

    • Understand the chain of custody for drug test specimens (including reporting and protocol),

    • Know the procedures for reviewing, interpreting and reporting results


There is a breadth of knowledge that MROs are expected to know inside and out, this includes:

  • Authorization of prescribed controlled substances consistent with the Drug Enforcement Agency (DEA) rules and regulations

  • Pharmacology of drugs of abuse

  • Accepted pharmacological treatment and standard prescribing practices

  • Ethical considerations in workplace testing programs

  • Laboratory testing methodology and quality control

  • Laws and regulations related to the use of illicit and licit substances

  • Chemical dependency and addiction behaviour

  • Employee assistance programs and rehabilitation

An MRO cannot be an agent or employee of any laboratory or Instrumental Test Facility (IITF). They can also not have any financial interest in the laboratory where they review the results of drug tests. They must always be impartial and void of any conflict of interest.


Medical Review Officers are an integral part of the drug and alcohol testing industry and a huge part of ensuring that all those tested are given a fair process where they are able to explain why their results are what they are, before the final verification is done by the MRO. MROs make sure that the testing process is fair for each entity involved, as well as legally defensible.


 MRO Roles and Responsibilities


MROs serve an important role in protecting an employee’s ability to defend/explain themselves so they are not falsely accused of using drugs illicitly. MROs carefully review results from labs to ensure their validity and ensure all reasonable steps were taken to prevent adulteration of the specimens as well as the correct screening and confirmation panels were used.

When handling collected specimen results the MRO must review every result whether it be positive, negative, substituted, adulterated, rejected, or invalid for testing. By being fastidious about the results the MRO reduces flaws and then must:

  • Ensure that all results are correctly reported to the Employer, Organization or Agency.

  • Recommend further testing if necessary

  • Maintain their records with confidentiality.


Examples of best practices for MROs include:

  • Ensuring the correct drug test panel was used and it was used properly

  • Verify that all collection procedures were followed to reduce errors

  • Get in touch with donors over the phone who have tested positive and attempt to collect factual medical history of current or recent prescriptions

  • Report results to EOAs in a timely manner



“Medical Review Officers.” US Department of Transportation, United States Department of Transportation, 29 May 2012, www.transportation.gov/odapc/mro.



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