Most studies on regional economic impact have utilized employment or employment income data. Recently, a few scholars have noticed the importance of nonemployment income sources in urban economies. Using decennial census data on Arizona towns from 1970 to 1990, this paper first examines the increasing importance of nonempolyment income sources in urban economies and the associations of nonemployment income sources with elderly population and metropolitan location. Then, this paper investigates the impact of nonemployment income on urban growth in the framework of economic base model. The regression results show that the impact of nonemployment income is significant in the increase of nonbasic income and becomes greater over time, and that the impact of transfer over time, and that the impact of transfer income on nonbasic income of transfer income on nonbasic income is stronger in smaller towns and the impact of investment income is stronger in larger towns.