Justice Scalia
delivered the opinion of the Court.
Respondent AT&T Technologies, Inc. (AT&T), manufactures electronics products at its Montgomery Works plant. The three petitioners, all of whom are women, have worked as hourly wage employees in that facility since the early 1970’s, and have been represented by respondent Local 1942, International Brotherhood of Electrical Workers, AFL-CIO. Until 1979 all hourly wage earners accrued competitive seniority exclusively on the basis of years spent in the plant, and a worker promoted to the more highly skilled and better paid “tester” positions retained this plantwide seniority. A collective-bargaining agreement executed by respondents on July 23, 1979, altered the manner of calculating tester seniority. Thenceforth a tester’s seniority was to be determined not by length of plantwide service, but by time actually spent as a tester (though it was possible to regain full plantwide seniority after spending five years as a tester and completing a prescribed training program). The present action arises from that contractual modification.
Petitioners became testers between 1978 and 1980. During a 1982 economic downturn their low seniority under the 1979 collective-bargaining agreement caused them to be selected for demotion; they would not have been demoted had the former plantwide seniority system remained in place. Claiming that the present seniority system was the product of an intent to discriminate on the basis of sex, petitioners filed complaints with the Equal Employment Opportunity Commission (EEOC) in April 1983. After the EEOC issued right-to-sue letters, petitioners in September 1983 filed the present lawsuit in the District Court for the Northern District of Illinois, and sought certification as class representatives for women employees of AT&T’s Montgomery Works plant who had lost plantwide seniority or whom the new system had deterred from seeking promotions to tester positions. Their complaint alleged that among hourly wage earners the tester positions had traditionally been held almost exclusively by men, and nontester positions principally by women, but that in the 1970’s an increasing number of women took the steps necessary to qualify for tester positions and exercised their seniority rights to become testers. They claimed that the 1979 alteration of the rules governing tester seniority was the product of a “conspir[acy] to change the seniority rules, in order to protect incumbent male testers and to discourage women from promoting into the traditionally-male tester jobs,” and that “[t]he purpose and the effect of this manipulation of seniority rules has been to protect male testers from the effects of the female testers’ greater plant seniority, and to discourage women from entering the traditionally-male tester jobs.” App. 20, 21-22.
On August 27, 1986, before deciding whether to certify the proposed class, the District Court granted respondents’ motion for summary judgment on the ground that petitioners had not filed their complaints with the EEOC within the applicable limitations period. 44 FEP Cases 1817, 1821. A divided panel of the Court of Appeals for the Seventh Circuit affirmed, concluding that petitioners’ claims were time barred because “the relevant discriminatory act that triggers the period of limitations occurs at the time an employee becomes subject to a facially neutral but discriminatory seniority system that the employee knows, or reasonably should know, is discriminatory.” 827 F. 2d 163, 167 (1987). We granted certiorari, 488 U. S. 887 (1988), to resolve a Circuit conflict on when the limitations period begins to run in a lawsuit arising out of a seniority system not alleged to be discriminatory on its face or as presently applied. Compare, e. g., case below with Cook v. Pan American World Airways, 771 F. 2d 635, 646 (CA2 1985), cert. denied, 474 U. S. 1109 (1986).
Section 706(e) of Title VII of the Civil Rights Act of 1964, 78 Stat. 260, as amended, provides that “[a] charge . . . shall be filed [with the EEOC] within [the applicable period] after the alleged unlawful employment practice occurred.” 42 U. S. C. §2000e-5(e). Assessing timeliness therefore “requires us to identify precisely the ‘unlawful employment practice’ of which [petitioners] complai[n].” Delaware State College v. Ricks, 449 U. S. 250, 257 (1980). Under § 703(a) of Title VII, it is an “unlawful employment practice” for an employer
“(1) ... to discriminate against any individual with respect to his compensation, terms, conditions, or privileges of employment, because of such individual’s race, color, religion, sex, or national origin; or
“(2) to limit, segregate, or classify his employees or applicants for employment in any way which would deprive or tend to deprive any individual of employment opportunities or otherwise adversely affect his status as an employee, because of such individual’s race, color, religion, sex, or national origin.” 42 U. S. C. §2000e-2(a).
Petitioners’ allegation of a disparate impact on men and women would ordinarily suffice to state a claim under § 703 (a)(2), since that provision reaches “practices that are fair in form, but discriminatory in operation,” Griggs v. Duke Power Co., 401 U. S. 424, 431 (1971); see Connecticut v. Teal, 457 U. S. 440, 446 (1982). “[Seniority systems,” however, “are afforded special treatment under Title VII,” Trans World Airlines, Inc. v. Hardison, 432 U. S. 63, 81 (1977), by reason of § 703(h), which states:
“Notwithstanding any other provision of this sub-chapter, it shall not be an unlawful employment practice for an employer to apply different standards of compensation, or different terms, conditions, or privileges of employment pursuant to a bona fide seniority . . . system, . . . provided that such differences are not the result of an intention to discriminate because of race, color, religion, sex, or national origin . . . .” 42 U. S. C. § 2000e-2(h).
We have construed this provision to mean that “absent a discriminatory purpose, the operation of a seniority system cannot be an unlawful employment practice even if the system has some discriminatory consequences.” Hardison, supra, at 82; see American Tobacco Co. v. Patterson, 456 U. S. 63, 65, 69 (1982). Thus, for liability to be incurred “there must be a finding of actual intent to discriminate on [statutorily proscribed] grounds on the part of those who negotiated or maintained the [seniority] system.” Pullman-Standard v. Swint, 456 U. S. 273, 289 (1982).
Petitioners do not allege that the seniority system treats similarly situated employees differently or that it has been operated in an intentionally discriminatory manner. Rather, they claim that its differential impact on the sexes is unlawful because the system “ha[d] its genesis in [sex] discrimination.” Teamsters v. United States, 431 U. S. 324, 356 (1977). Specifically, the complaint alleges that respondents “conspired to change the seniority rules, in order to protect incumbent male testers,” and that the resulting agreement effected a “manipulation of seniority rules” for that “purpose.” See App. 20-22 (emphasis added). This is in essence a claim of intentionally discriminatory alteration of their contractual rights. Seniority is a contractual right, Aaron, Reflections on the Legal Nature and Enforceability of Seniority Rights, 75 Harv. L. Rev. 1532, 1533 (1962), and a competitive seniority system establishes a “hierarchy [of such rights] ... according to which . . . various employment benefits are distributed,” Franks v. Bowman Transportation Co., 424 U. S. 747, 768 (1976). Under the collective-bargaining agreements in effect prior to 1979, each petitioner had earned the right to receive a favorable position in the hierarchy of seniority among testers (if and when she became a tester), and respondents eliminated those rights for reasons alleged to be discriminatory. Because this diminution in employment status occurred in 1979 — well outside the period of limitations for a complaint filed with the EEOC in 1983 — the Seventh Circuit was correct to find petitioners’ claims time barred under § 706(e).
We recognize, of course, that it is possible to establish a different theoretical construct: to regard the employer as having been guilty of a continuing violation which “occurred,” for purposes of § 706(e), not only when the contractual right was eliminated but also when each of the concrete effects of that elimination was felt. Or it would be possible to interpret § 703 in such fashion that when the proviso of § 703(h) is not met (“provided that such differences are not the result of an intention to discriminate because of race, color, religion, sex, or national origin”) and that subsection’s protection becomes unavailable, nothing prevents suits against the later effects of the system on disparate-impact grounds under § 703(a)(2). The answer to these alternative approaches is that our cases have rejected them.
The continuing violation theory is contradicted most clearly by two decisions, Delaware State College v. Ricks, 449 U. S. 250 (1980), and United Air Lines, Inc. v. Evans, 431 U. S. 553 (1977). In Ricks, we treated an allegedly discriminatory denial of tenure — rather than the resulting nondiscriminatory termination of employment one year later — as the act triggering the limitations period under § 706(e). Because Ricks did not claim that “the manner in which his employment was terminated differed discriminatorily from the manner in which the College terminated other professors who also had been denied tenure,” we held that “the only alleged discrimination occurred — and the filing limitations periods therefore commenced — at the time the tenure decision was made and communicated to Ricks.” 449 U. S., at 258. “That is so,” we found, “even though one of the effects of the denial of tenure — the eventual loss of a teaching position — did not occur until later.” Ibid, (emphasis in original). We concluded that “ ‘[t]he proper focus is upon the time of the discriminatory acts, not upon the time at which the consequences of the acts became most painful.’” Ibid, (emphasis in original); accord, Chardon v. Fernandez, 454 U. S. 6, 8 (1981) (per curiam).
In Evans, United Air Lines had discriminatorily dismissed the plaintiff after she had worked several years as a flight attendant, and when it rehired her some years later, gave her no seniority credit for her earlier service. Evans conceded that the discriminatory dismissal was time barred, but claimed that the seniority system impermissibly gave “present effect to a past act of discrimination.” 431 U. S., at 558. While agreeing with that assessment, we concluded under § 703(h) that “a challenge to a neutral system may not be predicated on the mere fact that a past event which has no present legal significance has affected the calculation of seniority credit, even if the past event might at one time have justified a valid claim against the employer.” Id,., at 560. Like Evans, petitioners in the present case have asserted a claim that is wholly dependent on discriminatory conduct occurring well outside the period of limitations, and cannot complain of a continuing violation.
The second alternative theory mentioned above would view § 703(h) as merely providing an affirmative defense to a cause of action brought under § 703(a)(2), rather than as making intentional discrimination an element of any Title VII action challenging a seniority system. The availability of this affirmative defense would not alter the fact that the claim asserted is one of discriminatory impact under § 703(a)(2), causing the statute of limitations to run from the time that impact is felt. As an original matter this is a plausible, and perhaps even the most natural, reading of § 703(h). (We have construed § 703(e), 42 U. S. C. §2000e-2(e) — which deals with bona fide occupational qualifications — in this fashion. See Dothard v. Rawlinson, 433 U. S. 321, 333 (1977).) But such an interpretation of § 703(h) is foreclosed by our cases, which treat the proof of discriminatory intent as a necessary element of Title VII actions challenging seniority systems. At least as concerns seniority plans, we have regarded subsection (h) not as a defense to the illegality described in subsection (a)(2), but as a provision that itself “delineates which employment practices are illegal and thereby prohibited and which are not.” Franks, 424 U. S., at 758. Thus, in American Tobacco Co. we determined § 703(h) to mean that “the fact that a seniority system has a discriminatory impact is not alone sufficient to invalidate the system; actual intent to discriminate must be proved.” 456 U. S., at 65 (emphasis added). “To be cognizable,” we held, “a claim that a seniority system has discriminatory impact must be accompanied by proof of a discriminatory purpose.” Id., at 69 (emphasis added); accord, Pullman-Standard, 456 U. S., at 277, 289; Hardison, 432 U. S., at 82. Indeed, in California Brewers Assn. v. Bryant, 444 U. S. 598 (1980), after deciding that a challenged policy was part of a seniority system, we noted that on remand to the District Court the plaintiff would “remain free to show that . . . the seniority system ... is not ‘bona fide’ or that the differences in employment conditions that it has produced are ‘the result of an intention to discriminate because of race,’” id., at 610-611. Thus, petitioners’ claim depends on proof of intentionally discriminatory adoption of the system, which occurred outside the limitations period.
That being the case, Machinists v. NLRB, 362 U. S. 411 (1960), establishes that the limitations period will run from the date the system was adopted (at least where the adoption occurred after the effective date of Title VII, and a cause of action against it was available). Machinists was a decision under the National Labor Relations Act (NLRA), but we have often observed that the NLRA was the model for Title VII’s remedial provisions, and have found cases interpreting the former persuasive in construing the latter. See Ford Motor Co. v. EEOC, 458 U. S. 219, 226, n. 8 (1982); Teamsters, 431 U. S., at 366; Franks, supra, at 768-770; Albemarle Paper Co. v. Moody, 422 U. S. 405, 419 (1975). Such reliance is particularly appropriate in the context presented here, since the highly unusual feature of requiring an administrative complaint before a civil action can be filed against a private party is common to the two statutes. The NLRA’s statute of limitations — which provides that “no complaint shall issue based upon any unfair labor practice occurring more than six months prior to the filing of the charge with the Board,” 29 U. S. C. § 160(b) — is even substantively similar to § 706(e) — which states that “[a] charge . . . shall be filed [with the EEOC] within one hundred and eighty days after the alleged unlawful employment practice occurred,” 42 U. S. C. §2000e-5(e). In Zipes v. Trans World Airlines, Inc., 455 U. S. 385 (1982), we specifically relied on cases construing the NLRA’s timely filing requirement in determining whether § 706(e) — the very provision we construe here — constituted a waivable statute of limitations or rather a jurisdictional prerequisite to a Title VII action. “Because the time requirement for filing an unfair labor practice charge under the National Labor Relations Act operates as a statute of limitations subject to recognized equitable doctrines and not as a restriction of the jurisdiction of the National Labor Relations Board,” we said, “the time limitations under Title VII should be treated likewise.” 455 U. S., at 395, n. 11 (citations omitted).
Machinists considered and rejected an approach to the limitations period identical to that advanced here. The suit involved the timeliness of an unfair labor practice complaint directed at a so-called “union security clause,” which required all employees to join the union within 45 days of the contract’s execution. Under the NLRB’s precedents, agreeing to such a clause when the union lacked majority status constituted an unfair labor practice, as did continued enforcement of the clause. 362 U. S., at 413-414. The agreement at issue in Machinists had been adopted more than six months before the complaint issued (outside the limitations period), but had been enforced well within the period of limitations. “Conceding that a complaint predicated on the execution of the agreement here challenged was barred by limitations,” the NLRB contended that “its complaint was nonetheless timely since it was ‘based upon’ the parties’ continued enforcement, within the period of limitations, of the union security clause.” Id., at 415 (emphasis in original). We found, however, that “the entire foundation of the unfair labor practice charged was the Union’s time-barred lack of majority status when the original collective-bargaining agreement was signed,” and that “[i]n the absence of that fact enforcement of this otherwise valid union security clause was wholly benign.” Id., at 417. “[W]here a complaint based upon that earlier event is time-barred,” we reasoned, “to permit the event itself” “to cloak with illegality that which was otherwise lawful” “in effect results in reviving a legally defunct unfair labor practice.” Ibid. This analysis is squarely in point here. Because the claimed invalidity of the facially nondiscriminatory and neutrally applied tester seniority system is wholly dependent on the alleged illegality of signing the underlying agreement, it is the date of that signing which governs the limitations period.
In holding that, when a seniority system is nondiscriminatory in form and application, it is the allegedly discriminatory adoption which triggers the limitations period, we respect not only §706(e)’s general “Value judgment concerning the point at which the interests in favor of protecting valid claims are outweighed by the interests in prohibiting the prosecution of stale [claims],’” Ricks, 449 U. S., at 260 (citation omitted), but also the considerations underlying the “special treatment” accorded to seniority systems under § 703(h), see Hardison, 432 U. S., at 81. This “special treatment” strikes a balance between the interests of those protected against discrimination by Title VII and those who work — perhaps for many years — in reliance upon the validity of a facially lawful seniority system. There is no doubt, of course, that a facially discriminatory seniority system (one that treats similarly situated employees differently) can be challenged at any time, and that even a facially neutral system, if it is adopted with unlawful discriminatory motive, can be challenged within the prescribed period after adoption. But allowing a facially neutral system to be challenged, and entitlements under it to be altered, many years after its adoption would disrupt those valid reliance interests that § 703(h) was meant to protect. In the context of the present case, a female tester could defeat the settled (and worked-for) expectations of her co-workers whenever she is demoted or not promoted under the new system, be that in 1983, 1993, 2003, or beyond. Indeed, a given plaintiff could in theory sue successively for not being promoted, for being demoted, for being laid off, and for not being awarded a sufficiently favorable pension, so long as these acts — even if nondiscriminatory in themselves — could be attributed to the 1979 change in seniority. Our past cases, to which we adhere today, have declined to follow an approach that has such disruptive implications.
* * *
For the foregoing reasons, the judgment of the Court of Appeals is
Affirmed.
Justice O’Connor took no part in the consideration or decision of this case.
The type of seniority at issue here is not “benefit seniority,” which is used to “compute noncompetitive benefits earned under the contract of employment,” Franks v. Bowman Transportation Co., 424 U. S. 747, 766 (1976) (emphasis added), but “competitive seniority,” which is “used to allocate entitlements to scarce benefits” such as promotion or nondemotion, id., at 766-767.
Under 42 U. S. C. § 2000e-5(e), a charge must be filed with the EEOC within 180 days of the alleged unfair employment practice unless the complainant has first instituted proceedings with a state or local agency, in which case the period is extended to a maximum of 300 days. Neither the District Court nor the Court of Appeals ruled on the applicable limitations period in the present case, since both courts concluded that petitioners’ claims were time barred even if the applicable period was 300 days. See 827 F. 2d 163, 165, and n. 2 (CA7 1987). We may for the same reason avoid ruling on that point here.
The dissent attempts to distinguish Delaware State College v. Ricks on the ground that there “[t]he allegedly discriminatory denial of tenure . . . served notice to the plaintiff that his termination a year later would come as a ‘delayed, but inevitable, consequence.’” Post, at 917 (emphasis in original; citation omitted). This builds on its earlier criticism that “[o]n the day AT&T’s seniority system was adopted, there was no reason to believe that a woman who exercised her plantwide seniority to become a tester would ever be demoted as a result of the new system,” so that at that point the prospect of petitioners’ suffering “concrete] harm” was “speculative.” Post, at 914 (emphasis in original). Of course the benefits of a seniority system, like those of an insurance policy payable upon the occurrence of a noninevitable event, are by their nature speculative — if only because they depend upon the employee’s continuing desire to work for the particular employer. But it makes no more sense to say that no “concrete harm” occurs when an employer provides a patently less desirable seniority guarantee than what the law requires, than it does to say that no concrete harm occurs when an insurance company delivers an accident insurance policy with a face value of $10,000, when what has been paid for is a face value of $25,000. It is true that the injury to the employee becomes substantially more concrete when the less desirable seniority system causes his demotion, just as the injury to the policyholder becomes substantially more concrete when the accident occurs and the payment is $15,000 less than it should be. But that is irrelevant to whether there was any concrete injury at the outset. What the dissent means by “concrete harm” is what Ricks, 449 U. S., at 258, referred to as the point at which the injury becomes “most painful” — and that case rejected it as the point of reference for liability. Accord, Chardon v. Fernandez, 454 U. S. 6, 8 (1981) (per curiam).
Like Ricks and United Air Lines, Inc. v. Evans, 431 U. S. 553 (1977), our decision in Machinists v. NLRB also rejected an attempt to cure untimeliness by asserting a continuing violation:
“The applicability of these principles cannot be avoided here by invoking the doctrine of continuing violation. It may be conceded that the continued enforcement, as well as the execution, of this collective bargaining agreement constitutes an unfair labor practice, and that these are two logically separate violations, independent in the sense that they can be described in discrete terms. Nevertheless, the vice in the enforcement of this agreement is manifestly not independent of the legality of its execution, as would be the case, for example, with an agreement invalid on its face or with one validly executed, but unlawfully administered.” 362 U. S., at 422-423.
The dissent is mistaken to equate the application of a facially neutral but discriminatorily adopted system with the application of a system that is facially discriminatory. See post, at 916-917. With a facially neutral system the discriminatory act occurs only at the time of adoption, for each application is nondiscriminatory (seniority accrues for men and women on an identical basis). But a facially discriminatory system (e. g., one that assigns men twice the seniority that women receive for the same amount of time served) by definition discriminates each time it is applied. This is a material difference for purposes of the analysis we employed in Evans and Ricks — which focuses on the timing of the discriminatory acts for purposes of the statute of limitations. It is also why the dissent’s citation, post, at 915, of Bazemore v. Friday, 478 U. S. 385 (1986) — in which “[ejach week’s paycheck . . . deliverfed] less to a black than to a similarly situated white,” id., at 395 — is misplaced.