concurring in the judgment.
Petitioner enforces two policies that treat pregnant employees less favorably than other employees who incur a temporary disability. First, they are denied seniority benefits during their absence from work and thereafter; second, they are denied sick pay during their absence. The Court holds that the former policy is unlawful whereas the latter is lawful. I concur in the Court’s judgment, but because I believe that its explanation of the legal distinction between the two policies may engender some confusion among those who must make compliance decisions on a day-to-day basis, I advance a separate, and rather pragmatic, basis for reconciling the two parts of the decision with each other and with General Electric Co. v. Gilbert, 429 U. S. 125.
The general problem is to decide when a company policy which attaches a special burden to the risk of absenteeism caused by pregnancy is a prima facie violation of the statutory prohibition against sex discrimination. The answer “always,” which I had thought quite plainly correct,1 is foreclosed by the Court’s holding in Gilbert. The answer “never” would seem *154to be dictated by the Court’s view that a discrimination against pregnancy is “not a gender-based discrimination at all.” 2 The Court has, however, made it clear that the correct answer is “sometimes.” Even though a plan which frankly and unambiguously discriminates against pregnancy is “facially neutral,” the Court will find it unlawful if it has a “discriminatory effect.” 3 The question, then, is how to identify this discriminatory effect.
Two possible answers are suggested by the Court. The Court seems to rely on (a) the difference between a benefit and a burden, and (b) the difference between § 703 (a) (2) and § 703 (a)(1). In my judgment, both of these differences are illusory.4 I agree with the Court that the effect of the respond*155ent’s seniority plan is significantly different from that of the General Electric disability plan in Gilbert, but I suggest that the difference may be described in this way: Although the Gilbert Court was unwilling to hold that discrimination against pregnancy — as compared with other physical disabilities — is discrimination on account of sex, it may nevertheless be true that discrimination against pregnant or formerly pregnant employees — as compared with other employees — does constitute sex discrimination. This distinction may be pragmatically expressed in terms of whether the employer has a policy which adversely affects a woman beyond the term of her pregnancy leave.
Although the opinion in Gilbert characterizes as “facially neutral” a company policy which differentiates between an absence caused by pregnancy and an absence caused by illness, the factual context of Gilbert limits the reach of that broad characterization. Under the Court’s reasoning, the disability plan in Gilbert did not discriminate against pregnant employees or formerly pregnant employees while they were working for the company. If an employee, whether pregnant or non-pregnant, contracted the measles, he or she would receive disability benefits; moreover, an employee returning from maternity leave would also receive those benefits. On the other hand, pregnancy, or an illness occurring while absent on maternity leave, was not covered.5 During that period of maternity leave, the pregnant woman was temporarily cut off from the benefits extended by the company’s plan. At all other times, the woman was treated the same as other employees in terms of her eligibility for the plan’s benefits.
*156The Company’s seniority plan in this case has a markedly different effect. In attempting to return to work, the formerly pregnant woman is deprived of all previously accumulated seniority. The policy affects both her ability to re-enter the work force, and her compensation when she does return.6 The Company argues that these effects are permissible because they flow from its initial decision to treat pregnancy as an unexcused absence. But this argument misconceives the scope of the protection afforded by Gilbert to such initial decisions. For the General Electric plan did not attach any consequences to the condition of pregnancy that extended beyond the period of maternity leave. Gilbert allowed the employer to treat pregnancy leave as a temporal gap in the full employment status of a woman. During that period, the employer may treat the employee in a manner consistent with the determination that pregnancy is not an illness.7 In this case, however, the Company’s seniority policy has an adverse impact on the employee’s status after pregnancy leave is terminated. The formerly pregnant person is permanently disadvantaged as compared to the rest of the work force. And since the persons adversely affected by this policy constitute an exclusively female class, the Company’s plan has an obvious discriminatory effect.8
*157Under this analysis, it is clear that petitioner’s seniority rule discriminating against formerly pregnant employees is invalid. It is equally clear that the denial of sick pay during maternity leave is consistent with the Gilbert rationale, since the Company was free to withhold those benefits during that period.9
As is evident from my dissent in Gilbert, I would prefer to decide this case on a simpler rationale. Since that preference is foreclosed by Gilbert, I concur in the Court’s judgment on the understanding that as the law now stands, although some discrimination against pregnancy — as compared with other physical disabilities — is permissible, discrimination against pregnant or formerly pregnant employees is not.
“An analysis of the effect of a company’s rules relating to absenteeism would be appropriate if those rules referred only to neutral criteria, such as whether an absence was voluntary or involuntary, or perhaps particularly costly. This case, however, does not involve rules of that kind.
“Rather, the rule at issue places the risk of absence caused by pregnancy in a class by itself. By definition, such a rule discriminates on account of sex; for it is the capacity to become pregnant which primarily differentiates the female from the male. The analysis is the same whether the rule relates to hiring, promotion, the acceptability of an excuse for absence, or-an exclusion from a disability insurance plan.” General Electric Co. v. Gilbert, 429 U. S. 125, 161-162 (Stevens, J., dissenting).
In Gilbert, supra, at 136, the Court held that "an exclusion of pregnancy from a disability-benefits plan providing general coverage is not a gender-based discrimination at all.” Consistently with that holding, the Court today states that a "decision not to treat pregnancy as a disease or disability for purposes of seniority retention is not on its face a discriminatory policy.” Ante, at 140.
Ante, at 141; 429 U. S., at 146 (Stewart, J., concurring); ibid. (BlackmuN, J., concurring in part).
Differences between benefits and burdens cannot provide a meaningful test of discrimination since, by hypothesis, the favored class is always benefited and the disfavored class is equally burdened. The grant of seniority is a benefit which is not shared by the burdened class; conversely, the denial of sick pay is a burden which the benefited class need not bear.
The Court’s second apparent ground of distinction is equally unsatisfactory. The Court suggests that its analysis of the seniority plan is different because that plan was attacked under § 703 (a) (2) of Title VII, not § 703 (a)(1). Again, I must confess that I do not understand the relevance of this distinction. It is true that §703 (a)(1) refers to "discrimination” and § 703 (a) (2) does not. But the Court itself recognizes that this is not significant since a violation of § 703 (a) (2) occurs when a facially neutral policy has a “discriminatory effect.” Ante, at 141 (emphasis added). The Court also suggests that § 703 (a) (1) may contain a requirement of intent not present in § 703 (a) (2). Whatever the merits of that suggestion, it is apparent that it does not form the basis for any differentiation between the two subparagraphs of § 703 in this case, since the Court expressly refuses to decide the issue. Ante, at 144.
See Gilbert, 429 U. S., at 129 n. 4. Although I have the greatest difficulty with the Court’s holding in Gilbert that it was permissible to refuse coverage for an illness contracted during maternity leave, I suppose this aspect of Gilbert may be explained by the notion that any illness occurring at that time is treated as though it were attributable to pregnancy, and therefore is embraced within the area of permissible discrimination against pregnancy.
Ante, at 138-139.
These two limitations — that the effect of the employer's policy be limited to the period of the pregnancy leave and that it be consistent with the determination that pregnancy is not an illness — serve to focus the disparate effect of the policy on pregnancy rather than on pregnant or formerly pregnant employees. Obviously, policies which attach a burden to pregnancy also burden pregnant or formerly pregnant persons. This consequence is allowed by Gilbert, but only to the extent that the focus of the policy is, as indicated above, on the physical condition rather than the person.
This analysis is consistent with the approach taken by lower courts to post -Gilbert claims of pregnancy-based discrimination, which have recognized that Gilbert has “nothing to do with foreclosing employment opportunity.” Cook v. Arentzen, 14 EPD ¶7544, p. 4702 (CA4 1977); *157MacLennan v. American Airlines, Inc., 440 F. Supp. 466 (Va. 1977) (addressing the question of when, if ever, an employer can require an employee to take pregnancy leave). This case does not pose the issue of when an employer may require an employee to take pregnancy leave. Ante, at 138 n. 1.
In his concurring opinion, Mr. Justice Powell seems to suggest that, even when the employer’s disparate treatment of a pregnant employee is limited to the period of the pregnancy leave, it may still violate Title VII if the company’s rule has a greater impact on one sex than another. Ante, at 151-152. If this analysis does not require an overruling of Gilbert it must be applied with great caution, since the laws of probability would invalidate an inordinate number of rules on such a theory. It is not clear to me what showing, beyond “mathematical exactitude,” see ante, at 152 n. 6, is necessary before this Court will hold that a classification, which is by definition gender specific, discriminates on the basis of sex. Usually, statistical disparities aid a court in determining whether -an apparently neutral classification is, in effect, gender or race specific. Here, of course, statistics would be unnecessary to prove that point. In all events, I agree with the Court that this issue is not presented to us in this case, and accordingly concur in the Court’s determination of the proper scope of the remand.