Estimates of the size and structure of recent alien immigration to the United States are made. Substituting these revised estimates in the Series II projections of the U.S. Bureau of the Census implies a future U.S. population smaller than that implied by the Census Bureau’s estimates of immigration. The analysis of Coale (1972)—which calculates the decline in native-born fertility required to accommodate immigration and, at the same time, maintain a stationary population—is replicated, using both the Census Bureau’s estimates and the revised estimates reported here. The revised estimates indicate a smaller reduction in native fertility and a smaller ultimate size of the stationary population than are implied by the Census Bureau’s immigration estimates. The importance of age structure in all of these calculations is demonstrated.