It is the final negative result the MRO reports after review. A test can be verified negative in two ways:

• The laboratory reported the specimen as negative.
• The laboratory reported a positive, but the MRO found a legitimate medical explanation, such as a valid prescription (49 CFR 40.137).

A verified negative does not mean the person takes no medications. In rare cases the MRO may still report a medical safety concern to the employer (49 CFR 40.327).