This work explores the relationship between municipal government debt and revenue diversification using a prism of institutional and fiscal interactions, concentrating on revenue fungibility effects over time and on the role of state-imposed constraints. A diversified revenue structure tends to stabilize revenue levels by balancing income-elastic and inelastic revenue sources. The impact of such diversity has been the subject of much research on expenditure and service levels among state and local governments. Considerably less research has been conducted on its potential relationship with debt, although capital financing is a necessary and often-utilized mechanism for funding capital and operational spending for local governments. Since it is well known that debt payments are fixed in the short run, they require sufficient revenue adequacy through economic highs and lows. It is thus argued that local governments with more diversified revenue structures are better able to utilize debt financing since revenue diversity mitigates the risk of borrowing by providing for greater fiscal predictability in the long run. This hypothesis is tested on two samples - a large sample of cities in Massachusetts from 2000 through 2009, as well as a cross-state sample, encompassing the cities from the majority of U.S. states. The findings of both studies provide preliminary evidence on the influence of revenue diversification on the levels of municipal indebtedness. While the Massachusetts study reveals that revenue diversification is, indeed, a statistically significant determinant of debt per capita, which also has an indirect effect on property tax burdens, the cross-state study suggests that revenue diversification has a mitigating impact on certain state-imposed fiscal rules, further adding to its weight as a strategic financial management tool. Both studies also reiterate the importance of such fiscal capacity factors as fund balances, intergovernmental revenue, and the size of government, while also revealing some new interaction patterns among various state-imposed debt limitations.