The federal doctrine of sex discrimination in employment depends on the underlying yet unstated assumption that sex is binary: one is either a man or a woman, and there is no other possibility. The existence of intersex individuals challenges this assumption. This article asks how Title VII doctrine can be applied to intersex employees. In answering, the Article considers (1) the ramifications of the ever-developing definition of “because of . . . sex” in Title VII jurisprudence as applied to sexual minorities and (2) the implications of Title VII doctrine regarding mixed-race individuals for our understanding of how the law treats (and should treat) individuals “in between” the categories. The article moves beyond previous work, which suggests that intersex individuals be protected as a third sex category under Title VII, because that work only reinforces the exact sex categorizations that should be undermined by any serious examination of intersexuality. Instead, the article proposes a new model for protection against sex discrimination in employment–that of discrimination “because of perceived sex.”