Although a "semantic receptive-expressive gap" appears to be a universal feature of early bilingualism, little is known about its development. We sought to determine if the magnitude of the discrepancy between receptive and expressive standard scores changed over time in bilingual children's two languages. In this longitudinal study, standardized receptive and expressive semantics tests of 106 Spanish-English bilingual children with TD were taken at kindergarten and first grade in both English and Spanish. We used a multivariate analysis approach to identify interactions and main effects. Although both receptive and expressive standard scores improved across the year in both languages, the magnitude of the gap was similar for both languages at both time points. However, there was greater improvement in English than in Spanish. Expressive scores at the end of the year were similar to receptive scores a year earlier. The magnitude of this gap remains relatively constant at kindergarten and first grade in both English and Spanish, despite overall improvements in semantic performance in both languages. There is on average roughly a one year lag between receptive and expressive semantics skills. Clinicians should take caution in interpreting receptive-expressive semantic gaps.