20 C.F.R. § 10.502
In considering the medical and factual evidence, OWCP will weigh the probative value of the attending physician's report, any second opinion physician's report, any other medical reports, or any other evidence in the file. If OWCP determines that the medical evidence supporting one conclusion is more consistent, logical, and well-reasoned than evidence supporting a contrary conclusion, OWCP will use the conclusion that is supported by the weight of the medical evidence as the basis for awarding or denying further benefits. If medical reports that are equally well-reasoned support inconsistent determinations of an issue under consideration, OWCP will direct the employee to undergo a third, impartial referee examination to resolve the issue, which will be given special weight in determining the issue.
20 C.F.R. § 10.502