A municipal bond, commonly known as a muni bond, is a bond issued by a local government or territory, or one of their agencies. It is generally used to finance public projects such as roads, schools, airports and seaports, and infrastructure-related repairs. The term municipal bond is commonly used in the United States, which has the largest market of such trade-able securities in the world. As of 2011, the municipal bond market was valued at $3.7 trillion. Potential issuers of municipal bonds include states, cities, counties, redevelopment agencies, special-purpose districts, school districts, public utility districts, publicly owned airports and seaports, and other governmental entities (or group of governments) at or below the state level having more than a de minimis amount of one of the three sovereign powers: the power of taxation, the power of eminent domain or the police power.
Municipal bonds may be general obligations of the issuer or secured by specified revenues. In the United States, interest income received by holders of municipal bonds is often excludable from gross income for federal income tax purposes under Section 103 of the Internal Revenue Code, and may be exempt from state income tax as well, depending on the applicable state income tax laws. The state and local exemption was the subject of litigation in Department of Revenue of Kentucky v. Davis.
Unlike new issue stocks that are brought to market with price restrictions until the deal is sold, most municipal bonds are free to trade at any time once they are purchased by the investor. Professional traders regularly trade and re-trade the same bonds several times a week. A feature of this market is a larger proportion of smaller retail investors compared to other sectors of the U.S. securities markets. Some municipal bonds, often with higher risk credits, are issued subject to transfer restrictions.
Outside the United States, many other countries in the world also issue similar bonds, sometimes called local authority bonds or other names. The key defining feature of such bonds is that they are issued by a public-use entity at a lower level of government than the sovereign. Such bonds follow similar market patterns as U.S. bonds. That said, the U.S. municipal bond market is unique for its size, liquidity, legal and tax structure and bankruptcy protection afforded by the U.S. Constitution.
Historically, municipal debt predates corporate debt by several centuries—the early Renaissance Italian city-states borrowed money from major banking families. Borrowing by American cities dates to the nineteenth century, and records of U.S. municipal bonds indicate use around the early 1800s. Officially the first recorded municipal bond was a general obligation bond issued by the City of New York for a canal in 1812. During the 1840s, many U.S. cities were in debt, and by 1843 cities had roughly $25 million in outstanding debt. In the ensuing decades, rapid urban development demonstrated a correspondingly explosive growth in municipal debt. The debt was used to finance both urban improvements and a growing system of free public education.
Years after the Civil War, significant local debt was issued to build railroads. Railroads were private corporations and these bonds were very similar to today's industrial revenue bonds. Construction costs in 1873 for one of the largest transcontinental railroads, the Northern Pacific, closed down access to new capital. Around the same time, the largest bank of the country of the time, which was owned by the same investor as that of Northern Pacific, collapsed. Smaller firms followed suit as well as the stock market. The 1873 panic and years of depression that followed put an abrupt but temporary halt to the rapid growth of municipal debt. Responding to widespread defaults that jolted the municipal bond market of the day, new state statutes were passed that restricted the issuance of local debt. Several states wrote these restrictions into their constitutions. Railroad bonds and their legality were widely challenged, and this gave rise to the market-wide demand that an opinion of qualified bond counsel accompany each new issue.
When the U.S. economy began to move forward once again, municipal debt continued its momentum, which was maintained well into the early part of the twentieth century. The Great Depression of the 1930s halted growth, although defaults were not as severe as in the 1870s. Leading up to World War II, many American resources were devoted to the military, and prewar municipal debt burst into a new period of rapid growth for an ever-increasing variety of uses. Today, in addition to the 50 states and their local governments (including cities, counties, villages and school districts), the District of Columbia and U.S. territories and possessions (American Samoa, the Commonwealth of Puerto Rico, Guam, the Northern Mariana Islands, and the U.S. virgin Islands) can and do issue municipal bonds. Another important category of municipal bond issuers which includes authorities and special districts has also grown in number and variety in recent years. The two most prominent early authorities were the Port of New York Authority, formed in 1921 and renamed Port Authority of New York and New Jersey in 1972, and the Triborough Bridge Authority (now the Triborough Bridge and Tunnel Authority), formed in 1933. The debt issues of these two authorities are exempt from federal, state and local governments taxes.
Municipal bonds provide tax exemption from federal taxes and many state and local taxes, depending on the laws of each state. Municipal securities consist of both short-term issues (often called notes, which typically mature in one year or less) and long-term issues (commonly known as bonds, which mature in more than one year). Short-term notes are used by an issuer to raise money for a variety of reasons: in anticipation of future revenues such as taxes, state or federal aid payments, and future bond issuances; to cover irregular cash flows; meet unanticipated deficits; and raise immediate capital for projects until long-term financing can be arranged. Bonds are usually sold to finance capital projects over the longer term.
The two basic types of municipal bonds are: