[713]*713Justice White
announced the judgment of the Court and delivered an opinion, Parts I, II, and III-A of which represent the views of the Court, and Parts III-B, IV, and V of which are joined by The Chief Justice, Justice Powell, and Justice Scalia.
This case involves the award of an attorney’s fee to the prevailing party pursuant to § 304(d) of the Clean Air Act, 42 U. S. C. § 7604(d).1
h-H
We set forth a detailed statement of the facts underlying this litigation in Pennsylvania v. Delaware Valley Citizens' [714]*714Council for Clean Air, 478 U. S. 546 (1986), and recite only an abbreviated version of those facts here. In 1977, the Delaware Valley Citizens’ Council for Clean Air (hereinafter respondent) and the United States each filed suit to compel the Commonwealth of Pennsylvania to comply with certain provisions of the Clean Air Act. The parties entered into a consent decree, approved by the District Court in 1978,2 which obligated the Commonwealth to establish a program for the inspection and maintenance of vehicle emissions systems in 10 counties in the Philadelphia and Pittsburgh areas by August 1, 1980. The Commonwealth failed to implement the program by this date, and protracted litigation ensued. Ultimately, in May 1983, the parties agreed to set June 1, 1984, as the date on which the Commonwealth would commence the inspection and maintenance program. Shortly after this agreement, respondent petitioned the District Court for attorney’s fees and costs for the work performed after the issuance of the consent decree. In determining the amount of fees to be awarded, the District Court divided the work performed by respondent’s counsel into nine phases. See 478 U. S., at 549-553. After computing the lodestar for each phase, the District Court adjusted this figure upward in phases four, five, and seven by doubling the lodestar to reflect the risk presumably faced by respondent that it would not prevail on these phases of the litigation. The District Court observed:
“The contingent nature of plaintiff’s success has been apparent throughout this litigation. Plaintiffs entered the litigation against the U. S. Government and the Commonwealth of Pennsylvania. The case involved new and novel issues, the resolution of which had little or no precedent. . . . [Plaintiffs have had to defend their rights under the consent decree due to numerous [715]*715attempts by defendants and others to overturn or circumvent this Court’s Orders.” 581 F. Supp. 1412, 1431 (1984).
The Court of Appeals for the Third Circuit affirmed the District Court’s enhancement of the fee award for contingency of success, 762 F. 2d 272, 282 (1985), a judgment that we now reverse.3
II
We first focus on the nature of the issue before us. Under the typical fee-shifting statute, attorney’s fees are awarded to a prevailing party and only to the extent that party prevails. See, e. g., Maher v. Gagne, 448 U. S. 122, 129-130 (1980); Hensley v. Eckerkart, 461 U. S. 424, 435 (1983). Hence, if the case is lost, the loser is awarded no fee; and unless its attorney has an agreement with the client that the attorney will be paid, win or lose, the attorney will not be paid at all. In such cases, the attorney assumes a risk of nonpayment when he takes the case. The issue before us is whether, when a plaintiff prevails, its attorney should or may be awarded separate compensation for assuming the risk of not being paid. That risk is measured by the risk of losing rather than winning and depends on how unsettled the applicable law is with respect to the issues posed by the [716]*716case and by how likely it is that the facts could be decided against the complainant. Looked at in this way, there are various factors that have little or no bearing on the question before us.
First is the matter of delay. When plaintiffs’ entitlement to attorney’s fees depends on success, their lawyers are not paid until a favorable decision finally eventuates, which may be years later, as in this case. Meanwhile, their expenses of doing business continue and must be met. In setting fees for prevailing counsel, the courts have regularly recognized the delay factor, either by basing the award on current rates or by adjusting the fee based on historical rates to reflect its present value. See, e. g., Sierra Club v. EPA, 248 U. S. App. D. C. 107, 120-121, 769 F. 2d 796, 809-810 (1985); Louisville Black Police Officers Organization, Inc. v. Louisville, 700 F. 2d 268, 276, 281 (CA6 1983). Although delay and the risk of nonpayment are often mentioned in the same breath, adjusting for the former is a distinct issue that is not involved in this case. We do not suggest, however, that adjustments for delay are inconsistent with the typical fee-shifting statute.
Second, that a case involves an issue of public importance, that the plaintiff’s position is unpopular in the community, or that defendant is difficult or obstreperous does not enter into assessing the risk of loss or determining whether that risk should be compensated. Neither does the chance that the court will find unnecessary and not compensate some of the time and effort spent on prosecuting the case.
Third, when the plaintiff has agreed to pay its attorney, win or lose, the attorney has not assumed the risk of nonpayment and there is no occasion to adjust the lodestar fee because the case was a risky one. See, e. g., Jones v. Central Soya Co., 748 F. 2d 586, 593 (CA11 1984), where the court said that “[a] lawyer may not preserve a right of recourse against his client for fees and still expect to be compensated [717]*717as if he had sacrificed completely his right to payment in the event of an unsuccessful outcome.”
r-H h — I ► — I
A
Although the issue of compensating for assuming the risk of nonpayment was left open in Blum v. Stenson, 465 U. S. 886 (1984), Justice Brennan wrote that “the risk of not prevailing, and therefore the risk of not recovering any attorney’s fees is a proper basis on which a district court may award an upward adjustment to an otherwise compensatory fee.” Id., at 902 (concurring). Most Courts of Appeals are of a similar view and have allowed upward adjustment of fee awards because of the risk of loss factor.4 The First Circuit, [718]*718in Wildman v. Lerner Stores Corp., 771 F. 2d 605 (1985), for example, takes this approach and allows an upward adjustment to the lodestar to account for the contingency factor. In that case, the District Court entered judgment on a jury verdict finding an employer liable for violating the Age Discrimination in Employment Act, 29 U. S. C. § 621 et seq., and two Puerto Rican statutes. The court awarded the prevailing party a lodestar fee amount of $56,500 and then increased that figure by 50% to account for the fact that because of the difficulties of the action and the novelty of the issue, “the plaintiffs’ attorneys . . . faced a contingency of losing all their time and effort.” 771 F. 2d, at 610. In sustaining the enhancement of fee awards based on contingency, the Court of Appeals relied on the legislative history of 42 U. S. C. § 1988, detailed several additional reasons as to why it is necessary to increase the lodestar figure for contingent-fee cases, and concluded that rather than compensating lawyers for unsuccessful claims, an adjustment of the lodestar figure may be necessary in particular cases to provide for the reasonable attorney’s fee envisioned by Congress.5
[719]*719This construction of the fee-shifting statutes has not been universal. The District of Columbia Circuit is particularly skeptical of the purpose served by enhancing the lodestar amount to account for the risk of not prevailing. In Laffey v. Northwest Airlines, Inc., 241 U. S. App. D. C. 11, 746 F. 2d 4 (1984), cert. denied, 472 U. S. 1021 (1985), the court reversed the trial court’s decision to double the lodestar based on the risk factor, citing a wide variety of problems with such an approach. The court found that, in theory, there should be no limit on the size of the fee if risk enhancement is permitted, for the less likely the chances of success in a particular case, the more “entitled” the prevailing party should be to have the fee award reflect acceptance of this risk. In a similar vein, the contingency factor penalizes the losing parties with the strongest and most reasonable defenses, thus “creating a perverse penalty for those least culpable.” 241 U. S. App. D. C., at 33, 746 F. 2d, at 26. Moreover, even if the risk of loss should be taken into account, “the chances of winning could not be set with anything approaching mathematical precision, and so vast increases in attorneys [fees] would derive from a spurious mathematical base.” Id., at 33-34, 746 F. 2d, at 26-27 (footnote omitted).
On a more fundamental level, the court found that using the risk of loss to increase the lodestar figure compensates attorneys not only for their successful efforts in one case, but for their unsuccessful claims asserted in related cases. This not only “encourag[es] marginal litigation,” but raises “the [720]*720reasonable question of ‘why the subsidy [for unsuccessful litigation] should come from the defendant in another case.’” Id., at 34, n. 138, 746 F. 2d, at 27, n. 138 (citations omitted).
Such a scheme was deemed to be manifestly inconsistent with Congress’ intent to award attorney’s fees only to prevailing parties. Relying on this Court’s holding in Hensley that attorney’s fees could not be awarded for claims unrelated to those on which the party ultimately prevailed, the court reasoned:
“The same logic which restricts compensation to those portions of a lawsuit directly related to the relief procured also forbids multiplying attorneys fees so as effectively to compensate counsel for other, losing claims which may be brought. The prevailing party may expect full compensation for prevailing claims; there is no provision for compensating losing, unrelated claims in the same case, or other losing cases which might or might not involve the same parties. Any crude multiplier derived simply from the plaintiff’s chance of success must be rejected as contrary to the congressional scheme.” Id., at 34-35, 746 F. 2d, at 27-28.
Finally, the court held that even if a contingency enhancement, as opposed to a contingency multiplier, could be used to reflect the party’s initial chance of success, Blum made clear that such enhancements were proper only in the most exceptional of cases, and because “this case did not present an exceptional level of risk, no risk enhancement should be awarded.” Id., at 36, 746 F. 2d, at 29.6
[721]*721The bar and legal commentators have been much interested in the issue.7 Some writers unqualifiedly have endorsed the concept of increasing the fee award to insure that lawyers will be adequately compensated for taking the risk of not prevailing. “The experience of the marketplace indicates that lawyers generally will not provide legal representation on a contingent basis unless they receive a premium for taking that risk.” Berger, Court Awarded Attorneys’ Fees: What is “Reasonable”?, 126 U. Pa. L. Rev. 281, 324-325 (1977).8 See also, Developments in the Law—Class Actions, 89 Harv. L. Rev. 1318, 1615 (1976); Comment, 122 U. Pa. L. Rev. 636, 708-711 (1974).
Others have been considerably more reserved in their endorsement of a contingency bonus, focusing on four major problems with the use of this factor. First, evaluation of the risk of loss creates a potential conflict of interest between an attorney and his client, for in order to increase a fee award, a plaintiff’s lawyer must expose all of the weaknesses [722]*722and inconsistencies in his client’s case, and a defendant’s attorney must either concede the strength of the plaintiff’s case in order to keep down the fee award, or “allo[w] the fee to be boosted by the contingency bonus [by] insisting that the plaintiff’s victory was freakish.” Leubsdorf, The Contingency Factor in Attorney Fee Awards, 90 Yale L. J. 473, 483 (1981) (Leubsdorf). Second, in order to determine the proper size of the contingency bonus, a court must retroactively estimate the prevailing party’s chances for success from the perspective of the attorney when he first considered filing the suit. Not only is this mathematically difficult to compute, but “once the result is known, it is hard for judges and lawyers to regain a perspective of ignorance and to treat the result as only one of several that were initially possible.” Id., at 486.
The third problem with increasing the fee award to account for the risk of not prevailing is the same one identified by the courts which have questioned this practice: it penalizes the defendant with the strongest defense, and forces him to subsidize the plaintiff’s attorney for bringing other unsuccessful actions against other defendants. Id., at 488-491. See Note, 80 Colum. L. Rev. 346, 375 (1980). Finally, because the contingency bonus cannot be determined with either certainty or accuracy, it “cannot be justified on the ground that it provides an appropriate incentive for litigation.” Leubsdorf 496. Cf. Note, 96 Harv. L. Rev. 677, 686, n. 51 (1983); Comment, 53 U. Chi. L. Rev. 1074 (1986).
There are other considerations. Fee-shifting removes the interest a paying client would have in ensuring that the lawyer is serving the client economically; the task of monitoring the attorney is shifted to the judge in separate litigation over fees if the plaintiff wins. Fee litigation occurs on a case-to-case basis and is often protracted, complicated, and exhausting. There is little doubt that it should be simplified to the maximum extent possible. If the decided cases are any measure, assessing the initial risk of loss when the case is [723]*723over is a particularly uncertain matter, especially for a judge who is confident that he has correctly decided for the plaintiff, but then must inquire how weak the plaintiff’s case was and how likely it was that he, the judge, would have been mistaken. It may be absurd to ask the judge to “determine the probability that he would have decided the case incorrectly.” Id., at 1094.
B
The disagreement among the Circuits and commentators indicates that Congress has not clearly directed or authorized multipliers or enhancements for assuming the risk of loss. Neither the Clean Air Act nor § 1988 expressly provides for using the risk of loss as an independent basis for increasing an otherwise reasonable fee, and it is doubtful that the legislative history supports .the use of this factor. In concluding that risk-enhancement is authorized, Justice Brennan in Blum, 465 U. S., at 902, relied on the fact that one of the items to be relied on in setting a fee and enumerated in Johnson v. Georgia Highway Express, Inc., 488 F. 2d 714 (CA5 1974), is whether the fee is fixed or contingent, and that Congress endorsed consideration of this factor. See S. Rep. No. 94-1011, p. 6 (1976) (S. Rep). But a careful reading of Johnson shows that the contingency factor was meant to focus judicial scrutiny solely on the existence of any contract for attorney’s fees which may have been executed between the party and his attorney. “The fee quoted to the client or the percentage of the recovery agreed to is helpful in demonstrating the attorney’s fee expectations when he accepted the case.” 488 F. 2d, at 718. See Leubsdorf 479, n. 38. At most, therefore, Johnson suggests that the nature of the fee contract between the client and his attorney should be taken into account when determining the reasonableness of a fee award, but there is nothing in Johnson to show that this factor was meant to reflect the contingent nature of prevailing in the lawsuit as a whole.
[724]*724Justice Brennan also noted that Congress cited Stanford Daily v. Zurcher, 64 F. R. D. 680 (ND Cal. 1974) (subsequently aff’d, 550 F. 2d 464 (CA9 1977), rev’d on other grounds, 436 U. S. 547 (1978)), as one of several cases which “correctly applied” the Johnson factors. Blum, supra, at 903. The court there increased the lodestar based, in part, on contingency-of-success considerations. But Congress also cited two other cases which it found also “correctly applied” the Johnson criteria. In Davis v. County of Los Angeles, 8 EPD ¶ 9444, p. 5047 (CD Cal. 1974), the District Court added a “Result Charge” to the basic fee award. This award was not intended to compensate the lawyers for assuming the risk of not prevailing on the merits; instead, as the label suggests, the court increased the - award because “counsel [had] achieved excellent results,” and “[t]he nature of the case made it difficult to litigate....” Id., at 5048. The court in Swann v. Charlotte-Mecklenburg Bd. of Ed., 66 F. R. D. 483 (WDNC 1975), the third illustrative case cited .with approval by Congress, did not increase the basic fee award at all. Instead, after reviewing nine factors similar to those listed in Johnson, the court reduced the prevailing party’s fee request by nearly 15%, choosing to “err on the conservative side in dealing with any fee question” rather than “contribute unnecessarily to the overpricing of litigation in this or any other court.” 66 F. R. D., at 486. Given the divergence in both analysis and result between these three cases, the legislative history is, at best, inconclusive in determining whether Congress endorsed the concept of increasing the lodestar amount to reflect the risk of not prevailing on the merits.
We must nevertheless come to a decision and have concluded that the judgment must be reversed.
IV
We are impressed with the view of the Court of Appeals for the District of Columbia Circuit that enhancing fees for [725]*725risk of loss forces losing defendants to compensate plaintiff’s lawyers for not prevailing against defendants in other cases.' This result is not consistent with Congress’ decision to adopt the rule that only prevailing parties are entitled to fees. If risk multipliers or enhancement are viewed as no more than compensating attorneys for their willingness to take the risk of loss and of nonpayment, we are nevertheless not at all sure that Congress intended that fees be denied when a plaintiff loses, but authorized payment for assuming the risk of an uncompensated loss. Such enhancement also penalizes the defendants who have the strongest case; and in theory, at least, would authorize the highest fees in cases least likely to be won and hence encourage the bringing of more risky cases, especially by lawyers whose time is not fully occupied with other work. Because it is difficult ever to be completely sure that a case will be won, enhancing fees for the assumption of the risk of nonpayment would justify some degree of enhancement in almost every case.
Weighing all of these considerations, we are unconvinced that Congress intended the risk of losing a lawsuit to be an independent basis for increasing the amount of any otherwise reasonable fee for the time and effort expended in prevailing. As the Senate Report observed: “In computing the fee, counsel for prevailing parties should be paid, as is traditional with attorneys compensated by a fee-paying client, ‘for all time reasonably expended on a matter.’ Davis, supra; Stanford Daily, supra, at 684.” S. Rep. 6.
The contrary argument is that without the promise of multipliers or enhancement for risk-taking, attorneys will not take cases for clients who cannot pay, and the fee-shifting statutes will therefore not serve their purpose. We agree that a fundamental aim of such statutes is to make it possible for those who cannot pay a lawyer for his time and effort to obtain competent counsel, this by providing lawyers with reasonable fees to be paid by the the losing defendants. But it does not follow that fee enhancement for risk is necessary [726]*726or allowable. Surely that is not the case where plaintiffs can afford to pay and have agreed to pay, win or lose. The same is true where any plaintiff, impecunious or otherwise, has a damages case that competent lawyers would take in the absence of fee-shifting statutes. Nor is it true in those cases where plaintiffs secure help from organizations whose very purpose is to provide legal help through salaried counsel to those who themselves cannot afford to pay a lawyer. It is also unlikely to be true in any market where there are competent lawyers whose time is not fully occupied by other matters.
The issue thus involves damages cases that lawyers would not take, not because they are too risky (the fee-shifting statutes should not encourage such suits to be brought), but because the damages likely to-be recovered are not sufficient to provide adequate compensation to counsel, as well as those frequent cases in which the goal is to secure injunctive relief to the exclusion of any claim for damages. In both situations, the fee-shifting statutes guarantee reasonable payment for the time and effort expended if the case is won. Respondent’s position is that without the prospect of being awarded fees exceeding such reasonable payment, plaintiffs with such cases will be unable to secure the help that the statutes aimed to provide.
We are not persuaded that this will be the case. Indeed, it may well be that using a contingency enhancement is superfluous and unnecessary under the lodestar approach to setting a fee. The reasons a particular lawsuit are considered to be “risky” for an attorney are because of the novelty and difficulty of the issues presented, and because of the potential for protracted litigation. Moreover, when an attorney ultimately prevails in such a lawsuit, this success will be primarily attributable to his legal skills and experience, and to the hours of hard work he devoted to the case. These factors, however, are considered by the court in determining the reasonable number of hours expended and the reasonable hourly [727]*727rate for the lodestar, and any further increase in this sum based on the risk of not prevailing would result not in a “reasonable” attorney’s fee, but in a windfall for an attorney who prevailed in a difficult case.9
It may be that without the promise of risk enhancement some lawyers will decline to take cases; but we doubt that the bar in general will so often be unable to respond that the goal of the fee-shifting statutes will not be achieved. In any event, risk enhancement involves difficulties in administration and possible inequities to those who must pay attorney’s fees; and in the absence of further legislative guidance, we conclude that multipliers or other enhancement of a reasonable lodestar fee to compensate for assuming the risk of loss is impermissible under the usual fee-shifting statutes.
[728]*728Even if § 304(d) and other typical fee-shifting statutes are construed to permit supplementing the lodestar in appropriate cases by paying counsel for assuming the risk of nonpayment, for the reasons set out below, it was error to do so in this case.
V
Section 304(d), like § 1988, does not indicate that adjustment for risk should be the rule rather than the exception; neither does it require such an adjustment in any case. At most, it leaves the matter of risk enhancement to the informed discretion of the courts. There are, however, severe difficulties and possible inequities involved in making upward adjustments for assuming the risk of nonpayment, and we deem it appropriate, in order to guide the exercise of the trial courts’ discretion in awarding fees, to adopt here the approach followed in Blum in dealing with other multipliers. As in that case, payment for the time and effort involved— the lodestar — is presumed to be the reasonable fee authorized by the statute, and enhancement for the risk of nonpayment should be reserved for exceptional cases where the need and justification for such enhancement are readily apparent and are supported by evidence in the record and specific findings by the courts.10 Blum, 465 U. S., at 898-901. [729]*729For several reasons, the circumstances of this case do not justify the risk multiplier employed by the District Court.
First, the District Court doubled the lodestar in three phases of the case in recognition of the risk of loss, saying that the “contingent nature of plaintiffs’ success has been apparent” from the outset, that plaintiffs entered the litigation against the United States and the Commonwealth of Pennsylvania, and that the case involved new and novel issues, the resolution of which had little or no precedent. Furthermore, they had to “defend their rights under the consent decree due to numerous attempts by defendants and others to overturn or circumvent this court’s orders.” 581 F. Supp., at 1431. This case, however, concerns only the reasonable fee for work done after the consent decree was entered, and fees have already been awarded for work done before that time. The risk of nonpayment should be determined at the beginning of the litigation. Lewis v. Coughlin, 801 F. 2d 570, 576 (CA2 1986); Ramos v. Lamm, 713 F. 2d 546, 558 (CA10 1983).11 Whatever counsel thought the risk of losing was at [730]*730the outset, it is doubtful that counsel anticipated a similar risk in enforcing a decree if plaintiff was successful in having one entered. In any event, the District Court did not specifically identify any new and novel issues, and we fail to discern any, that emerged in the long process of enforcing the court decree in accordance with its terms. And whether the Commonwealth of Pennsylvania was a substantial opponent or whether it tried to circumvent the decree has little or nothing to do with whether the there was a real risk of not persuading the District Court to enforce its own decree. The matter may have been difficult, wearing, and time consuming, but that kind of effort has been recognized in the lodestar award.
Second, if it be assumed that this is one of the exceptional cases in which enhancement for assuming the risk of nonpayment is justified, we conclude that doubling the lodestar for certain phases of the work was excessive. We have alluded to the uncertainties involved in determining the risk of not prevailing and the burdensome nature of fee litigation. We deem it desirable and an appropriate application of the statute to hold that if the trial court specifically finds that there was a real risk-of-not-prevailing issue in the case, an upward adjustment of the lodestar may be made, but, as a general rule, in an amount no more than one-third of the lodestar. Any additional adjustment would require the most exacting justification. This limitation will at once protect against windfalls for attorneys and act as some deterrence against bringing suits in which the the attorney believes there is less than a 50-50 chance of prevailing. Riskier suits may be brought, and if won, a reasonable lodestar may be awarded, but risk enhancement will be limited to one-third of the lodestar, if awarded at all. Here, even assuming an adjustment for risk was justified, the multiplier employed was excessive.
Third, whatever the risk of winning or losing in a specific case might be, a fee award should be informed by the statutory purpose of making it possible for poor clients with good [731]*731claims to secure competent help. Before adjusting for risk assumption, there should be evidence in the record, and the trial court should so find, that without risk enhancement plaintiff would have faced substantial difficulties in finding counsel in the local or other relevant market.12 Here, there were no such findings.
Accordingly, the judgment of the Court of Appeals is
Reversed.