28 CFR § 52.01 - Civil proceedings: Special master, pretrial, trial, appeal.
(a) Sections 636 (b) and (c) of title 28 of the United States Code govern pretrial and case-dispositive civil jurisdiction of magistrate judges, as well as service by magistrate judges as special masters.
(b) It is the policy of the Department of Justice to encourage the use of magistrate judges, as set forth in this paragraph, to assist the district courts in resolving civil disputes. In conformity with this policy, the attorney for the government is encouraged to accede to a referral of an entire civil action for disposition by a magistrate judge, or to consent to designation of a magistrate judge as special master, if the attorney, with the concurrence of his or her supervisor, determines that such a referral or designation is in the interest of the United States. In making this determination, the attorney shall consider all relevant factors, including—
(1) The complexity of the matter, including involvement of significant rights of large numbers of persons;
(2) The relief sought;
(3) The amount in controversy;
(4) The novelty, importance, and nature of the issues raised;
(5) The likelihood that referral to or designation of the magistrate judge will expedite resolution of the litigation;
(6) The experience and qualifications of the magistrate judge; and
(7) The possibility of the magistrate judge's actual or apparent bias or conflict of interest.
(c)
(1) In determining whether to consent to having an appeal taken to the district court rather than to the court of appeals, the attorney for the government should consider all relevant factors including—
(i) The amount in controversy;
(ii) The importance of the questions of law involved;
(iii) The desirability of expeditious review of the magistrate judge's judgment.
(2) In making a determination under paragraph (c)(1) of this section the attorney shall, except in those cases in which delegation authority has been exercised under 28 CFR 0.168, consult with the Assistant Attorney General having supervisory authority over the subject matter.