We modeled how variation in size of home ranges and annual movements of white-tailed deer (Odocoileus virginianus) in southern Texas altered ability to manage deer within various sizes of management units and discussed implications for spread of disease. The percentage of adult (≥3.5 years) males remaining on management units varied <4% across three sites in southern Texas. The spatial extent of spread of disease by adult males would be less than movements associated with migration or dispersal. Based on size of home ranges and movements, >98% of males would use management units of 1,000 km² because their use of space would not result in use of adjoining management units. Migration of deer in northern latitudes resulted in 20% of the population using management units of 1,000 km², which potentially could expose large areas (>25,000 km²) to disease because a greater percentage of deer would use adjoining management units compared to deer in southern latitudes. Our results are useful in determining size and configuration of management units, which will improve formulation of management plans, analysis of data from harvests, and prediction and control of disease.