Empirical studies and theories of government–nonprofit relationships have assumed a unidirectional funding flow from governments to nonprofits and therefore focusing on the impact of governments on nonprofits. By articulating multiple mechanisms of how nonprofits may influence government spending and utilizing a unique panel dataset that contains nonprofit and local government spending on parks, this article tests several prominent theoretical models of government–nonprofit relationships to answer the question of how spending by park-supporting charities influences the level of public spending on parks and recreation services. The findings indicate that spending by park-supporting charities spending has a decreasing effect on the level of public operational spending on parks, which supports the supplementary model. However, there is a net gain in total community support for parks and recreation services. Finally, this article suggests that government–nonprofit relationships are not identical when funding sources for public service provision differ in subsectors. A two-way understanding is essential for the theory building and testing in government–nonprofit relationships.