Justice Marshall
delivered the opinion of the Court.
In 1976, Congress amended §101 of the Federal Magistrates Act, 28 U. S. C. § 636, to provide that a United States district judge may refer dispositive pretrial motions, and petitions for writ of habeas corpus, to a magistrate, who shall conduct appropriate proceedings and recommend dispositions. Pub. L. 94-577, 90 Stat. 2729. The amendments also provide that any party that disagrees with the magistrate’s recommendations "may serve and file written objections” to the magistrate’s report, and thus obtain de novo review by the district judge. The question presented is whether a court of appeals may exercise its supervisory powers to establish a rule that the failure to file objections to the magistrate’s report waives the right to appeal the district court’s judgment. We hold that it may.
b-i
Petitioner was convicted by an Ohio court m 1978 of fatally shooting her common-law husband during an argument. The evidence at trial showed that the victim was a violent man who had beaten petitioner on a number of occasions during the previous three years. Petitioner raised the issue of self-defense at trial, and sought to call two witnesses who would present expert testimony concerning the Battered Wife Syndrome. After conducting a voir dire of these witnesses in chambers, the trial court refused to admit the testimony, on the grounds that the jury did not need the assistance of expert testimony to understand the case and that the witnesses, who had not personally examined petitioner, could not testify about her state of mind at the time of the shooting.
The Court of Appeals of Cuyahoga County reversed. State v. Thomas, 64 Ohio App. 2d 141, 411 N. E. 2d 845 (1979). The court’s syllabus concluded that testimony concerning the Battered Wife Syndrome is admissible “to afford the jury an understanding of the defendant’s state of mind at the time she committed the homicide.” App. 9. The Ohio Supreme Court, on discretionary review, reversed. State v. Thomas, 66 Ohio St. 2d 518, 423 N. E. 2d 137 (1981). The court held that the testimony was irrelevant to the issue of self-defense, and that its prejudicial effect would outweigh its probative value. Having exhausted state remedies, petitioner sought habeas corpus relief in the United States District Court for the Northern District of Ohio. The petition raised, inter alia, the question whether petitioner was denied a fair trial by the trial court’s refusal to admit testimony concerning the Battered Wife Syndrome. Petitioner filed a memorandum of law in support of the petition. The District Judge, acting pursuant to 28 U. S. C. § 636(b)(1)(B), referred the case, including petitioner’s memorandum of law, to a Magistrate. The Magistrate did not hold a hearing. On May 11, 1982, the Magistrate issued his report, containing proposed findings of fact and conclusions of law and recommending that the writ be denied. On the issue of the Battered Wife Syndrome testimony, the Magistrate concluded that the trial court’s failure to admit the proffered testimony had not impaired the fundamental fairness of the trial, and therefore was not an adequate ground for habeas corpus relief.
The last page of the Magistrate’s report contained the prominent legend:
“ANY OBJECTIONS to this Report and Recommendation must be filed with the Clerk of Courts within ten (10) days of receipt of this notice. Failure to file objections within the specified time waives the right to appeal the District Court’s order. See: United States v. Walters, 638 F. 2d 947 (6th Cir. 1981).”
Despite this clear notice, petitioner failed to file objections at any time. She sought and received an extension of time to file objections through June 15, 1982, on the grounds that “this case entails many substantive issues and counsel needs more time to write his brief.” However, petitioner made no further submissions on the merits to the District Court. Notwithstanding petitioner’s failure to file objections, the District Judge sua sponte “review[ed] . . . the entire record de novo,” App. 59, and dismissed the petition on the merits. Petitioner sought and was granted leave to appeal.
Petitioner’s brief on appeal raised only the issue of the Battered Wife Syndrome testimony. The brief provided no explanation for petitioner’s failure to object to the Magistrate’s report. Counsel for petitioner waived oral argument, and the case was decided on the briefs. The Court of Appeals for the Sixth Circuit affirmed. 728 F. 2d 813 (1984). Without reaching the merits, it held that petitioner had waived the right to appeal by failing to file objections to the Magistrate’s report. Id., at 815. The court relied upon its prior decision in United States v. Walters, 638 F. 2d 947 (1981), which established the prospective rule that failure to file timely objections with the district court waives subsequent review in the court of appeals. We granted the petition for a writ of cer-tiorari, 470 U. S. 1027 (1985), and we now affirm.
I — 1 1 — I
In United States v. Walters, supra, the appellant failed to object to the Magistrate’s report, and the District Court adopted that report as its disposition of the case. The appellant then brought an appeal. The Court of Appeals for the Sixth Circuit considered the threshold question whether the appellant’s failure to apprise the District Court of its disagreement with the Magistrate’s recommendation waived the right to appeal. The court held:
“The permissive language of 28 U. S. C. §636 suggests that a party’s failure to file objections is not a waiver of appellate review. However, the fundamental congressional policy underlying the Magistrate’s Act — to improve access to the federal courts and aid the efficient administration of justice — is best served by our holding that a party shall file objections with the district court or else waive right to appeal. Additionally, through the exercise of our supervisory power, we hold that a party shall be informed by the magistrate that objections must be filed within ten days or further appeal is waived.
“However, we give our ruling only prospective effect because rules of procedure should promote, not defeat the ends of justice . . . .” Id., at 949-950 (footnote and citations omitted).
The nature of the rule and its prospective application demonstrate that the court intended to adopt a “rul[e] of procedure,” id., at 950, in the exercise of its supervisory powers. Later opinions of the Sixth Circuit make it clear that the court views Walters in this way. See Patterson v. Mintzes, 717 F. 2d 284, 286 (1983) (“In Walters . . . this Court promulgated [a] rule of waiver”); United States v. Martin, 704 F. 2d 267, 275 (1983) (Jones, J., concurring) (characterizing Wal ters as “[rjulemaking through the exercise of supervisory-powers”). Thus, petitioner’s first contention — that the Court of Appeals has refused to exercise the jurisdiction that Congress granted it — is simply inaccurate. The Court of Appeals expressly acknowledged that it had subject-matter jurisdiction over petitioner’s appeal. 728 F. 2d, at 814. The Sixth Circuit has also shown that its rule is not jurisdictional by excusing the procedural default in a recent case. See Patterson v. Mintzes, supra (considering appeal on merits despite pro se litigant’s late filing of objections). We therefore conclude that neither the intent nor the practical effect of the Sixth Circuit’s waiver rule is to restrict the court’s own jurisdiction.
I — I HH hH
It cannot be doubted that the courts of appeals have supervisory powers that permit, at the least, the promulgation of procedural rules governing the management of litigation. Cf. Cuyler v. Sullivan, 446 U. S. 335, 346, n. 10 (1980) (approving exercise of supervisory powers to require district court inquiry concerning joint representation of criminal defendants). Indeed, this Court has acknowledged the power of the courts of appeals to mandate “procedures deemed desirable from the viewpoint of sound judicial practice although in nowise commanded by statute or by the Constitution.” Cupp v. Naughten, 414 U. S. 141, 146 (1973); see also Barker v. Wingo, 407 U. S. 514, 530, n. 29 (1972). Had petitioner failed to comply with a scheduling order or pay a filing fee established by a court of appeals, that court could certainly dismiss the appeal. Cf. Link v. Wabash R. Co., 370 U. S. 626 (1962) (recognizing “inherent power” of court to dismiss case for want of prosecution). The fact that the Sixth Circuit has deemed petitioner to have forfeited her statutory right to an appeal is not enough, standing alone, to invalidate the court’s exercise of its supervisory power.
The Sixth Circuit’s decision to require the filing of objections is supported by sound considerations of judicial economy. The filing of objections to a magistrate’s report enables the district judge to focus attention on those issues — factual and legal — that are at the heart of the parties’ dispute. The Sixth Circuit’s rule, by precluding appellate review of any issue not contained in objections, prevents a litigant from “sandbagging” the district judge by failing to object and then appealing. Absent such a rule, any issue before the magistrate would be a proper subject for appellate review. This would either force the court of appeals to consider claims that were never reviewed by the district court, or force the district court to review every issue in every case, no matter how thorough the magistrate’s analysis and even if both parties were satisfied with the magistrate’s report. Either result would be an inefficient use of judicial resources. In short, “[t]he same rationale that prevents a party from raising an issue before a circuit court of appeals that was not raised before the district court applies here.” United States v. Schronce, 727 F. 2d 91, 94 (CA4) (footnote omitted), cert. denied, 467 U. S. 1208 (1984).
IV
Even a sensible and efficient use of the supervisory power, however, is invalid if it conflicts with constitutional or statutory provisions. A contrary result “would confer on the judiciary discretionary power to disregard the considered limitations of the law it is charged with enforcing.” United States v. Payner, 447 U. S. 727, 737 (1980). Thus we now consider whether the Sixth Circuit’s waiver rule conflicts with statutory law or with the Constitution.
A
Petitioner argues that the Federal Magistrates Act precludes the waiver rule adopted by the Sixth Circuit. Her argument focuses on the permissive nature of the statutory language. The statute provides that a litigant “may” file objections, and nowhere states that the failure to do so will waive an appeal. Petitioner cites the Eighth Circuit’s conclusion that “[o]ne would think that if Congress had wished such a drastic consequence to follow from the missing of the ten-day time limit, it would have said so explicitly.” Lorin Corp. v. Goto & Co., 700 F. 2d 1202, 1206 (1983). However, we need not decide whether the Act mandates a waiver of appellate review absent objections. We hold only that it does not forbid such a rule.
Section 636(b)(1)(C) provides that “[a] judge of the [district] court shall make a de novo determination of those portions of the report or specified proposed findings or recommendations to which objection is made.” The statute does not on its face require any review at all, by either the district court or the court of appeals, of any issue that is not the subject of-an objection. Petitioner argues, however, that the statutory language and purpose implicitly require the district court to review a magistrate’s report even if no party objects. If petitioner’s interpretation of the statute is correct, then the waiver of appellate review, as formulated by the Sixth and other Circuits, proceeds from an erroneous assumption— that the failure to object may constitute a procedural default waiving review even at the district court level. Moreover, were the district judge required to review the magistrate’s report in every case, the waiver of appellate review would not promote judicial economy as discussed in Part III, supra.
Petitioner first argues that a failure to object waives only de novo review, and that the district judge must still review the magistrate’s report under some lesser standard. However, § 636(b)(1)(C) simply does not provide for such review. This omission does not seem to be inadvertent, because Congress provided for a “clearly erroneous or contrary to law” standard of review of a magistrate’s disposition of certain pretrial matters in § 636(b)(1)(A). See Park Motor Mart, Inc. v. Ford Motor Co., 616 F. 2d 603, 605 (CA1 1980). Nor does petitioner point to anything in the legislative history of the 1976 amendments mandating review under some lesser standard. We are therefore not persuaded that the statute positively requires some lesser review by the district court when no objections are filed.
Petitioner also argues that, under the Act, the obligatory filing of objections extends only to findings of fact. She urges that Congress, in order to vest final authority over questions of law in an Article III judge, intended that the district judge would automatically review the magistrate’s conclusions of law. We reject, however, petitioner’s distinction between factual and legal issues. Once again, the plain language of the statute recognizes no such distinction. We also fail to find such a requirement in the legislative history.
It does not appear that Congress intended to require district court review of a magistrate’s factual or legal conclusions, under a de novo or any other standard, when neither party objects to those findings. The House and Senate Reports accompanying the 1976 amendments do not expressly consider what sort of review the district court should perform when no party objects to the magistrate’s report. See S. Rep. No. 94-625, pp. 9-10 (1976) (hereafter Senate Report); H. R. Rep. No. 94-1609, p. 11 (1976) (hereafter House Report). There is nothing in those Reports, however, that demonstrates an intent to require the district court to give any more consideration to the magistrate’s report than the court considers appropriate. Moreover, the Subcommittee that drafted and held hearings on the 1976 amendments had before it the guidelines of the Administrative Office of the United States Courts concerning the efficient use of magistrates. Those guidelines recommended to the district courts that “[w]here a magistrate makes a finding or ruling on a motion or an issue, his determination should become that of the district court, unless specific objection is filed within a reasonable time.” See Jurisdiction of United States Magistrates, Hearings on S. 1283 before the Subcommittee on Improvements in Judicial Machinery of the Senate Committee on the Judiciary, 94th Cong., 1st Sess., 24 (1975) (emphasis added) (hereafter Senate Hearings). The Committee also heard Judge Metzner of the Southern District of New York, the chairman of a Judicial Conference Committee on the administration of the magistrate system, testify that he personally followed that practice. See id., at 11 (“If any objections come in,... I review [the record] and decide it. If no objections come in, I merely sign the magistrate’s order”). The Judicial Conference of the United States, which supported the de novo standard of review eventually incorporated in § 636(b)(1)(C), opined that in most instances no party would object to the magistrate’s recommendation, and the litigation would terminate with the judge’s adoption of the magistrate’s report. See Senate Hearings, at 35, 37. Congress apparently assumed, therefore, that any party who was dissatisfied for any reason with the magistrate’s report would file objections, and those objections would trigger district court review. There is no indication that Congress, in enacting § 636(b)(1)(C), intended to require a district judge to review a magistrate’s report to which no objections are filed. It did not preclude treating the failure to object as a procedural default, waiving the right to further consideration of any sort. We thus find nothing in the statute or the legislative history that convinces us that Congress intended to forbid a rule such as the one adopted by the Sixth Circuit.
Nor is the waiver of appellate review inconsistent with the purposes of the Act. The Act grew out of Congress’ desire to give district judges “additional assistance” in dealing with a caseload that was increasing far more rapidly than the number of judgeships. Mathews v. Weber, 423 U. S. 261, 268 (1976). Congress did not intend district judges “to devote a substantial portion of their available time to various procedural steps rather than to the trial itself.” House Report, at 7. Nor does the legislative history indicate that Congress intended this task merely to be transferred to the court of appeals. It seems clear that Congress would not have wanted district judges to devote time to reviewing magistrate’s reports except to the extent that such review is requested by the parties or otherwise necessitated by Article III of the Constitution. We now turn to the latter question.
B
Petitioner contends that the waiver of appellate review violates Article III and the Due Process Clause of the Fifth Amendment. Article III vests the judicial power of the United States in judges who have life tenure and protection from decreases in salary. Although a magistrate is not an Article III judge, this Court has held that a district court may refer dispositive motions to a magistrate for a recommendation so long as “the entire process takes place under the district court’s total control and jurisdiction,” United States v. Raddatz, 447 U. S. 667, 681 (1980), and the judge “‘exercisets] the ultimate authority to issue an appropriate order,”’ id., at 682, quoting Senate Report, at 3. The Sixth Circuit’s rule, as petitioner sees it, permits a magistrate to exercise the Article III judicial power, because the rule forecloses meaningful review of a magistrate’s report at both the district and appellate levels if no objections are filed.
We find that argument untenable. The waiver of appellate review does not implicate Article III, because it is the district court, not the court of appeals, that must exercise supervision over the magistrate. Even assuming, however, that the effect of the Sixth Circuit’s rule is to permit both the district judge and the court of appeals to refuse to review a magistrate’s report absent timely objection, we do not believe that the rule elevates the magistrate from an adjunct to the functional equivalent of an Article III judge. The rule merely establishes a procedural default that has no effect on the magistrate’s or the court’s jurisdiction. The district judge has jurisdiction over the case at all times. He retains full authority to decide whether to refer a case to the magistrate, to review the magistrate’s report, and to enter judgment. Any party that desires plenary consideration by the Article III judge of any issue need only ask. Moreover, while the statute does not require the judge to review an issue de novo if no objections are filed, it does not preclude further review by the district judge, sua sponte or at the request of a party, under a de novo or any other standard. Indeed, in the present case, the District Judge made a de novo determination of the petition despite petitioner’s failure even to suggest that the Magistrate erred. The Sixth Circuit’s rule, therefore, has not removed “ ‘the essential attributes of the judicial power,’” Northern Pipeline Co. v. Marathon Pipe Line Co., 458 U. S. 50, 77 (1982) (plurality opinion), quoting Crowell v. Benson, 285 U. S. 22, 51 (1932), from the Article III tribunal.
Petitioner claims also that she was denied her statutory-right of appeal, in violation of the Due Process Clause. That right was not denied, however; it was merely conditioned upon the filing of a piece of paper. Petitioner was notified in unambiguous terms of the consequences of a failure to file, and deliberately failed to file nevertheless. We recently reiterated our longstanding maxim that “the State certainly accords due process when it terminates a claim for failure to comply with a reasonable procedural or evidentiary rule.” Logan v. Zimmerman Brush Co., 455 U. S. 422, 437 (1982). The same rationale applies to the forfeiture of an appeal, and we believe that the Sixth Circuit’s rule is reasonable. Litigants subject to the Sixth Circuit’s rule are afforded “‘an opportunity . . . granted at a meaningful time and in a meaningful manner,’” ibid., quoting Armstrong v. Manzo, 380 U. S. 545, 552 (1965), to obtain a hearing by the Court of Appeals. We also emphasize that, because the rule is a nonjurisdictional waiver provision, the Court of Appeals may excuse the default in the interests of justice.
V
We hold that a court of appeals may adopt a rule conditioning appeal, when taken from a district court judgment that adopts a magistrate’s recommendation, upon the filing of objections with the district court identifying those issues on which further review is desired. Such a rule, at least when it incorporates clear notice to the litigants and an opportunity to seek an extension of time for filing objections, is a valid exercise of the supervisory power that does not violate either the Federal Magistrates Act or the Constitution. The judgment of the Court of Appeals is
Affirmed.
Title 28 U. S. C. § 636(b)(1)(B) provides:
“[A] judge may also designate a magistrate to conduct hearings, including evidentiary hearings, and to submit to a judge of the court proposed findings of fact and recommendations for the disposition, by a judge of the court, of any motion excepted in subparagraph (A), of applications for posttrial relief made by individuals convicted of criminal offenses and of prisoner petitions challenging conditions of confinement.”
The motions excepted in § 636(b)(1)(A), and included by reference in subparagraph (B), are motions
“for injunctive relief, for judgment on the pleadings, for summary judgment, to dismiss or quash an indictment or information made by the defendant, to suppress evidence in a criminal case, to dismiss or to permit maintenance of a class action, to dismiss for failure to state a claim upon which relief can be granted, and to involuntarily dismiss an action.”
Title 28 U. S. C. § 636(b)(1)(C) provides:
“[T]he magistrate shall file his proposed findings and recommendations under subparagraph (B) with the court and a copy shall forthwith be mailed to all parties.
“Within ten days after being served with a copy, any party may serve and file written objections to such proposed findings and recommendations as provided by rules of court. A judge of the court shall make a de novo determination of those portions of the report or specified proposed findings or recommendations to which objection is made. A judge of the court may accept, reject, or modify, in whole or in part, the findings or recommendations made by the magistrate. The judge may also receive further evidence or recommit the matter to the magistrate with instructions.”
In Ohio, the court’s syllabus contains the controlling law. See Engle v. Isaac, 456 U. S. 107, 111, n. 3 (1982), citing Haas v. State, 103 Ohio St. 1, 7-8, 132 N. E. 158, 159-160 (1921).
The First, Second, Fourth, and Fifth Circuits have adopted waiver rules similar to the Sixth Circuit rule at issue in the present case. See Park Motor Mart, Inc. v. Ford Motor Co., 616 F. 2d 603 (CA1 1980); McCarthy v. Manson, 714 F. 2d 234, 237 (CA2 1983); United States v. Schronce, 727 F. 2d 91 (CA4), cert. denied, 467 U. S. 1208 (1984); United States v. Lewis, 621 F. 2d 1382, 1386 (CA5 1980), cert. denied, 450 U. S. 935 (1981). The Ninth and Eleventh Circuits have concluded that the failure to file objections waives only factual issues on the appeal. See Britt v. Simi Valley Unified School District, 708 F. 2d 452, 454 (CA9 1983) (order denying petition for rehearing); Nettles v. Wainwright, 677 F. 2d 404 (CA5 1982) (en banc); but see Lorin Corp. v. Goto & Co., 700 F. 2d 1202, 1205-1207 (CA81983) (rejecting waiver rule, at least where parties had not been notified that failure to object would waive appeal). In none of these cases have the courts spoken in jurisdictional terms.
This power rests on the firmest ground when used to establish rules of judicial procedure. See Beale, Reconsidering Supervisory Power in Criminal Cases: Constitutional and Statutory Limits on the Authority of the Federal Courts, 84 Colum. L. Rev. 1433, 1465 (1984) (federal courts have inherent authority to regulate “technical details and policies intrinsic to the litigation process”). The Courts of Appeals have often exercised that authority. See, e. g., Tingler v. Marshall, 716 F. 2d 1109, 1112 (CA6 1983) (establishing procedure for sua sponte dismissal of complaints); United States v. Florea, 541 F. 2d 568, 572 (CA6 1976) (prospective rule holding that contact between party’s agent and juror is per se prejudicial), cert. denied, 430 U. S. 945 (1977); United States v. Schiavo, 504 F. 2d 1, 7-8 (CA3) (en banc) (establishing procedures for enjoining publication of information concerning criminal trial), cert, denied sub nom. Ditter v. Philadelphia Newspapers, Inc., 419 U. S. 1096 (1974).
In the present case, the filing of objections could have resulted in a considerable saving of judicial time. The original petition contained several grounds for relief, but on appeal petitioner raised only the issue of the admissibility of expert testimony on the Battered Wife Syndrome. Had petitioner objected only to that aspect of the Magistrate’s report, the Magistrate’s review would have served to narrow the dispute for the District Judge, and petitioner would have preserved her right to appeal the exclusion of her expert testimony.
The Sixth Circuit, in Walters, cited with approval the First Circuit’s decision in Park Motor Mart, which held that “a party ‘may’ file objections within ten days or he may not, as he chooses, but he ‘shall’ do so if he wishes further consideration.” 616 F. 2d, at 605; see Walters, 638 F. 2d, at 950. See also McCarthy v. Manson, 714 F. 2d, at 237 (“When a party fails to object timely to a magistrate’s recommended decision, it waives any right to further judicial review of that decision”) (footnote and citation omitted).
This is so even though the category of dispositive matters subject to de novo review by the district judge as of right only upon filing of objections includes motions for judgment on the pleadings and dismissal for failure to state a claim on which relief can be granted, which consist exclusively of issues of law. See n. 1, supra.
Petitioner points to a passage in the House Report that quotes from Campbell v. United States District Court, 501 F. 2d 196, 206 (CA9), cert. denied, 419 U. S. 879 (1974). The Ninth Circuit concluded: “If neither party contests the magistrate’s proposed findings of fact, the court may assume their correctness and decide the motion on the applicable law.” See House Report, at 3. However, that statement was part of a longer quotation setting a de novo review standard when objections are filed. The House Report stated that a House amendment, which called for de novo review in the same circumstances, was “adopted” from the Ninth Circuit’s decision in Campbell. House Report, at 3. We believe, therefore, that the House Report used the language from Campbell only to support a de novo standard upon the filing of objections, and not for any other proposition.
Indeed, Judge Metzner specifically addressed the difference between a magistrate’s ruling on a nondispositive motion, which Congress clearly “intended to be ‘final’ unless a judge of the court exercises his ultimate authority to reconsider the magistrate’s determination,” Senate Report, at 8, and a ruling on a dispositive motion. Judge Metzner concluded: “I think we are talking more about form, than we are of substance.” Senate Hearings, at 12.
Moreover, both Judge Metzner and the Judicial Conference were of the opinion that Congress could probably vest magistrates with the authority to make a final decision on dispositive motions without violating Article III, and that the language of § 636(b)(1)(B), calling for the magistrate to make only recommendations on dispositive motions, was adopted out of an abundance of caution. See Senate Hearings, at 6 (statement of Judge Metzner); id., at 35 (report of Judicial Conference of the United States). While we express no view on the accuracy of those opinions, we think they are relevant to Congress’ intent. See also House Report, at 8 (“it is not feasible for every judicial act, at every stage of the proceeding, to be performed by ‘a judge of the court’ ”).
See Senate Hearings, at 32 (statement of William P. Westphal, Chief Counsel) (filing objections as provided in the statute “is the procedure for them to follow, if they feel aggrieved by any of these motions”).
The 1976 amendments were prompted by this Court’s decision in Wingo v. Wedding, 418 U. S. 461 (1974). That case held that Congress had not intended, in enacting the Federal Magistrates Act in 1968, to permit a magistrate to conduct an evidentiary hearing on a habeas corpus petition. Congress enacted the 1976 amendments to “restat[e] and clarif[y]” Congress’ intent to permit magistrates to hold evidentiary hearings and perform other judicial functions. See Senate Report, at 3.
Article III, § 1, of the Constitution provides:
“The judicial Power of the United States, shall be vested in one supreme Court, and in such inferior Courts as the Congress may from time to time ordain and establish. The Judges, both of the supreme and inferior Courts, shall hold their Offices during good Behaviour, and shall, at stated Times, receive for their Services, a Compensation, which shall not be diminished during their Continuance in Office.”
The plurality in Northern Pipeline, and the concurrence in Raddatz, noted that the magistrate himself remains under the district court’s authority. The magistrate is appointed, and subject to removal, by the district court. See Northern Pipeline, 458 U. S., at 79, and n. 30; Raddatz, 447 U. S., at 685 (Blackmun, J., concurring) (“[T]he only conceivable danger of a ‘threat’ to the ‘independence’ of the magistrate comes from within, rather than without, the judicial department”). Those observations, of course, are also relevant here, and again weigh on the side of concluding that a magistrate remains an adjunct even though the district court and the court of appeals may refuse to entertain issues that are not raised in properly filed objections.
Cf. Fed. Rule Crim. Proe. 520)) (court may correct plain error despite failure of party to object). We need not decide at this time what standards the courts of appeals must apply in considering exceptions to their waiver rules.