The Medical Review Officer (MRO) is a specialized, licensed physician who acts as an impartial gatekeeper in the workplace drug and alcohol testing process. This role ensures the accuracy and integrity of testing results while protecting the rights and confidentiality of the individual being tested. The MRO is the final step in determining a verified test result, bridging the gap between laboratory science and the medical and administrative needs of the employer. Understanding the MRO’s duties is important, as this officer holds the authority to overturn a preliminary positive result.
Defining the Medical Review Officer Role
A Medical Review Officer must be a licensed physician, holding either a Doctor of Medicine (MD) or Doctor of Osteopathy (DO) degree. Beyond a standard medical license, the MRO must complete specific training and pass an examination demonstrating expert knowledge in the pharmacology and toxicology of illicit substances and prescription medications. This specialized training is often mandated by regulatory bodies like the Department of Health and Human Services (HHS) or the Department of Transportation (DOT), ensuring standardized competence.
The MRO must be independent, meaning they cannot be an employee or have a financial interest in the drug testing laboratory itself. This separation maintains strict impartiality, ensuring the MRO’s final determination is neutral between the employer’s interest in a safe workplace and the donor’s right to a fair evaluation. The MRO’s function is solely to review, verify, and interpret the entire testing record.
The MRO’s Review Process
The MRO’s work begins with the non-interactive phase, where they receive and examine the test results and documentation package from the laboratory. The laboratory provides a result categorized as negative, positive, substituted, adulterated, or invalid, along with the original Chain of Custody (COC) form. The initial “positive” result reported by the lab is always considered preliminary until the MRO completes the review.
The administrative review involves checking the COC form for procedural or administrative errors that could invalidate the test. The MRO looks for “fatal flaws,” such as a missing signature from the collector or a lack of specimen seals, which require the test to be canceled because the sample’s integrity cannot be guaranteed. If minor administrative issues, known as “correctable flaws,” are found, the MRO must contact the collection site or lab to resolve the issue before proceeding with verification.
The Verification Interview
If the laboratory reports a non-negative result (e.g., confirmed positive, adulterated, or substituted), the MRO initiates the confidential interview with the donor. This mandatory conversation provides the employee or applicant the opportunity to offer a legitimate medical explanation for the preliminary result. The MRO must attempt to contact the donor multiple times, often within 24 hours, before contacting the employer for assistance.
During the interview, the MRO explains the laboratory finding, including the specific substance detected or the basis for the substitution or adulteration finding. The donor must provide evidence of a valid prescription or other verifiable medical condition that accounts for the substance’s presence. The standard of proof rests with the donor, who must produce documentation like a current, legally valid prescription or medical records that the MRO can verify with the prescribing physician or pharmacy.
If the MRO confirms the legitimate medical explanation, the result is reported to the employer as a Verified Negative, despite the substance being present. If no legitimate medical reason is provided, or if the donor fails to cooperate, the MRO issues a Verified Positive result or a Refusal to Test determination. Following a Verified Positive result, the donor maintains the right to request a re-test of the original split specimen (“B specimen”) at a different certified laboratory.
Confidentiality and Regulatory Framework
The MRO functions as a privacy buffer, managing the flow of sensitive health information. When reporting the final outcome to the employer, the MRO only communicates the ultimate determination: Verified Positive, Verified Negative, or Refusal to Test. They are prohibited from disclosing specific medical information, such as the type of medication or the underlying medical condition that led to a Verified Negative result.
This protocol is governed by a regulatory framework, particularly for safety-sensitive positions regulated by the Department of Transportation (DOT) under 49 CFR Part 40. While the Health Insurance Portability and Accountability Act (HIPAA) generally protects health information, DOT regulations explicitly mandate the MRO’s duties. The MRO is generally not required to obtain an employee’s written authorization to verify prescriptions with a treating physician. However, the MRO must maintain detailed records and protect the donor’s privacy by reporting only the final fitness-for-duty determination, not the specific medical details.