On-site screening tests vary in sensitivity, particularly for detection of marijuana; it is common for false-negatives to occur. However, screening tests generally produce a very low level of false positives. If a sample is negative for drugs using an on-site test, no other testing takes place on it. However, when a sample tests positive on the screening test, it is sent to a laboratory for confirmation. A physician who specializes in the analysis of drug test results and is certified as a Medical Review Officer verifies that the positive test result is not due to a prescribed medication, dietary supplement, or other substance(2). This ensures that in each case of a positive result on an initial drug test, the result is confirmed and verified as not being the result of a prescribed medicine. However, a student could face consequences for a positive test during the confirmation period. As a result, we recommend that schools only direct consequences for a positive test (including informing relevant personnel and families) once the confirmation is complete and the positive result is verified.