This rulemaking would adopt the drug testing panel identified by the U.S. Department of Health and Human Services (HHS) in their urine and oral fluid Mandatory Guidelines for Federal Workplace Drug Testing Programs by proposing to amend the Department of Transportation's Drug Testing Panel in 49 CFR part 40 by adding Fentanyl and norfentanyl (Schedule II drugs). This rulemaking would also amend certain provisions of the Department of Transportation's drug testing regulation at 49 CFR part 40 dealing with laboratory testing of urine and oral fluid specimens. Some of the proposed changes would revise the role of the Medical Review Officer (MRO) regarding the conduct of clinical examinations. The proposed changes are intended to create consistency, as needed, with the recently updated drug testing requirements established by the Department of Health and Human Services (HHS) in its Mandatory Guidelines (MG) for urine and oral fluid.