Local governments, including cities, towns and villages, are responsible for building and maintaining much of the nation’s infrastructure. Almost half of the nation’s road miles and bridges are owned by local governments, along with the water and wastewater systems that serve residents. The quality of roads, bridges, water systems and public utilities reflects not only development priorities but also the financial capacity of local governments. The crucial financial tool they rely on is municipal bonds.
What Are Municipal Bonds?
Municipal bonds are debt instruments issued by state and local governments to finance public infrastructure projects.
Investors who purchase these bonds lend capital to governments in exchange for periodic interest payments and the return of principal at maturity. These bonds are structured as General Obligation (GO) bonds, backed by the municipalities’ taxing authority, or Revenue Bonds, which are repaid through income generated by specific projects such as toll roads, airports or water utilities. These bonds are tax-exempt and are being used by both state and local governments to finance most of their infrastructure. Municipalities align their financing structures with the type of infrastructure and their ability to generate revenue, making municipal bonds highly adaptable across project types.
Unmatched Scale of the Municipal Bond Market
Municipal bonds are not just one of many funding mechanisms — they are the majority of infrastructure financing (PDF) in the United States. State and local governments account for nearly 75 percent of all public infrastructure spending, and municipal bonds play a central role in enabling this investment. Between 2009 to 2019, approximately $4.2 trillion in municipal bonds were issued, reflecting the scale at which these debt instruments support development. By comparison, the state and local municipal bonding rate is about twice as much as the last federal infrastructure bill’s spending rate.
In 2025 alone, about $525 billion in municipal bonds (PDF) were issued, resulting in approximately $4.3 to $4.4 trillion in outstanding debt as of 2025. Of the 90,000 local government units (PDF) tracked by the Census Bureau, one-third use municipal bonds for funding infrastructure projects (PDF). This sustained growth reflects strong investor demand and the ongoing need for infrastructure investment.
Municipal Bonds Fund Essential Infrastructure Projects
Municipal bonds play a direct role in financing infrastructure projects. They are used to fund the construction of new assets, the rehabilitation of aging systems and the expansion of existing infrastructure to meet population growth and economic demand. One of their key strengths lies in enabling long-term capital planning. Infrastructure projects often have a lifespan of 20 to 50 years, and municipal bonds allow governments to match financing timelines with asset lifecycles. This ensures that the cost of infrastructure is distributed across the generations that benefit from it.
Transportation systems, including highways, public transit and airports, are among the largest recipients of bond financing. Water and wastewater systems also rely heavily on municipal bonds, particularly as cities face increasing pressure to replace aging pipes, improve water quality and meet environmental regulations. Education infrastructure, such as primary and secondary schools, is another major area supported by bond issuance, enabling communities to invest in modern facilities and accommodate growing student populations.
According to the Municipal Securities Rulemaking Board’s (MSRB) Municipal Market Facts (PDF), municipal bond proceeds are widely distributed across essential sectors. About $120.1 billion is for the use of bonds on General Purpose/Public Projects; next is $101 billion for Primary and Secondary Education; last is around $46.1 billion for Water and Sewer Facilities. These investments are not limited to core infrastructure — they also include public safety facilities, healthcare buildings and community development projects that enhance quality of life.
Infrastructure Needs and the Funding Gap
Despite the scale and efficiency of the municipal bond market, a significant gap persists between infrastructure needs and available funding. The Municipal Infrastructure Conditions 2025 (MIC) (PDF) report highlights the growing strain on local governments. Cities, towns and villages continue to prioritize investments in water systems, roads and bridges, recognizing their importance for economic growth and public well-being. However, rising construction costs, limited capital budgets and constrained access to revenue-raising methods (PDF) have made it increasingly difficult to meet these needs.
This reliance underscores the importance of the bond market while also revealing the financial pressures municipalities face. As infrastructure systems age and demands increase, the gap between required investment and available resources continues to widen. Additionally, without revenue raising capabilities, municipalities do face ceilings on their ability to bond, making them more reliant on state and federal supports such as one-time grants.
Municipal Bonds and Climate Resilience
Amid growing concerns about climate risk and infrastructure vulnerability, municipal bonds have emerged as a critical financing tool for building resilience. Municipal bonds are increasingly being used to address climate risks and support resilient infrastructure. In discussions led by NLC, city leaders emphasized the role of bonds in preparing for natural disasters such as hurricanes, wildfires and earthquakes. These events highlight the need for proactive investment in resilient systems that can withstand environmental stress.
Experiences from cities such as New Orleans demonstrate the importance of having strong financial tools in place to recover from major disasters, reinforcing the role of municipal bonds in both preparedness and recovery. Bonds have also been used to fund projects focused on community health and expanding the role of municipal bonds beyond traditional infrastructure. Hampton, Va., for example, experimented with Environmental Impact Bonds (EIBs). The city issued these bonds to fund major projects on roads, stormwater, parks and education.
Conclusion
As infrastructure needs evolve, municipal bonds are adapting to new challenges and continue to be the most impactful municipal finance tool available to communities. The growth of green bonds and social bonds (PDF) reflects a shift toward more sustainable and inclusive financing.
Municipal bonds remain a cornerstone of infrastructure financing, enabling local governments to build, maintain and modernize essential systems. Their scale, flexibility and cost advantages make them indispensable in addressing the complex challenges of infrastructure development.
However, as highlighted by the MIC 2025 report, the gap between infrastructure needs and available funding continues to grow. Bridging this gap will require not only sustained reliance on municipal bonds but also innovation, strategic planning and stronger financial frameworks. As cities navigate an increasingly complex landscape, municipal bonds will continue to play a central role in shaping resilient, equitable and sustainable communities.