In this paper we model the structures found in the level (generation) and allocation (distribution) components of age-specific and origin-destination-specific migration flows. For the examples, we examine the regional migration patterns in the USA for four periods: 1955-60, 1965-70, 1975-80, and 1985-90. The age and migration structures are identified over time by using the logit model for categorical data. Just as model schedules can be used to capture the age patterns of fertility, mortality, and migration rates for use in indirect estimation, so too the models set out in this paper can be used to capture the spatidal patterns exhibited by particular sets of age-specific and origin-destination-specific migration proportions. They then also can be used to impose these patterns on inaccurate, incomplete, or otherwise inadequate data.