Some scholars argue that Latina/os in the United States may soon become White, much like the supposed Whitening of Eastern European immigrant groups in the early twentieth century. High rates of White racial identification on surveys among Latina/os is one explanation provided for this assertion. However, personal identification is but one element of racial boundary maintenance. It is when personal identification is externally validated that it is most closely associated with group-based experiences. This article maps components of the White-Latino racial boundary that may be permeable to White expansion by examining conditions under which Latina/os self-identify as White and report that they are externally classified as White by other Americans. Employing novel data from the 2006 Portraits of American Life Study, this article shows that nearly 40% of Latina/os sometimes self-identify as White, yet a much smaller proportion—only 6%—report being externally classified as White by others. Moreover, logistic regression analyses suggest that for those with light phenotypical features and high levels of socioeconomic status, the odds of reported external Whitening are increased. Interestingly, phenotypically light Latina/os with low-socioeconomic-status levels have low probabilities of reporting external classification as White when compared to their phenotypically light and high-socioeconomic-status counterparts, suggesting that the combination of both skin color and class may be central to the White-Latino racial boundary. Results also indicate that many who report external Whitening do not prefer to self-identify as White. In sum, multidimensional measures of racial classification indicate that only a very small minority of Latina/os may be “becoming White” in ways that some previous researchers have predicted.