Current immigration research has revealed little about how immigrants compare to those who do not migrate. Although most scholars agree that migrants are not random samples of their home countries' populations, the direction and degree of educational selectivity is not fully understood. This study of 32 U.S. immigrant groups found that although nearly all immigrants are more educated than those who remain in their home countries, immigrants vary substantially in their degree of selectivity, depending upon the origin country and the timing of migration. Uncovering patterns of immigrant selectivity reveals the fallacy in attributing immigrants' characteristics to national groups as a whole and may help explain socioeconomic differences among immigrant groups in the United States.