Population change in Germany at the sub-national level is particularly driven by changes in net international migration and overall internal migration patterns, namely between urbanization, suburbanization and counter-urbanization. Official population projections at the county level only consist of one scenario, thereby omitting uncertainty that arises from changing patterns in the assumed components of demographic change. We use a cohort-component model that incorporates the spatial distribution of a net number of international migrants and internal migration matrices to provide population projections for 401 counties in Germany until 2070, encompassing a range of nine international and internal migration scenarios. Our results highlight the variability in possible population change in terms of population structure, size, and spatial distribution. According to our scenarios, the total projected population of Germany is expected to range between 74.25 to 86.84 million people. There are considerable differences in expected population change both spatially (e.g. between urban and rural areas) and concerning county population age structure, depending on the assumed absolute level of net international migration as well as the direction of internal migratory patterns. Our results highlight the large role internal and international migration patterns will play in future population development in Germany at the county level. We also discuss what our results and the uncertainty of future population change at the regional level mean for local policy making and planning.