A disputed result should be handled methodically. Preserve deadlines first, obtain the governing documents, and identify whether the issue concerns identity, collection, laboratory analysis, medical explanation, policy, or legal interpretation.
Act on the notice, not assumptions
Record the date and method of receipt. Calendar deadlines for MRO contact, split-specimen testing, B-sample analysis, grievance, administrative review, or appeal. Missing a deadline can end an option regardless of the merits.
Request the governing procedure
Obtain the employer policy, regulation, court order, probation condition, treatment agreement, sports rule, or school manual. Identify the decision maker, burden, available retest, costs, representation rights, and confidentiality rules.
Build the record
- Collection notice, consent, and custody forms.
- Specimen identifiers, dates, seals, and transport records.
- Screening and confirmation analytes, cutoffs, concentrations, and methods.
- Specimen-validity results and laboratory status.
- MRO communications and medication documentation.
- Corrected reports, quality-control records, and relevant correspondence.
Identify the type of challenge
Identity or custody: mismatched identifiers, undocumented transfers, broken seals, or labeling errors. Analytical: method, calibration, interference, cutoff, carryover, or reporting concerns. Medical: prescription, metabolism, or clinical explanation. Policy: unauthorized test, wrong panel, notice failure, or inconsistent procedure. Interpretive: a conclusion such as impairment or timing that exceeds the data.
Use the official retest mechanism
A split specimen or B sample is different from collecting a new sample days later. The official second portion can address the original specimen. Follow authorized laboratory and chain-of-custody procedures; private testing may not preserve rights unless the program accepts it.
Communicate carefully
Keep correspondence factual. Do not speculate publicly, alter records, discard medication or supplement packaging, or pressure laboratory staff outside the designated process. Provide health information to the authorized reviewer.
When to seek help
Qualified help is especially important when the outcome affects employment, a license, court supervision, custody, athletics, immigration, or treatment. Relevant professionals can include an MRO, clinical toxicologist, laboratory expert, union representative, compliance specialist, or attorney.
Realistic outcomes
A review may confirm the result, correct the record, identify a legitimate medical explanation, order another analysis, or determine that a policy consequence was unsupported. A disagreement alone does not establish laboratory error; evidence and the governing rule matter.
Related: Retesting and Disputes, Evidence and Appeals, and Decision Guides.