A municipal bond is a loan you make to a city, county, or state — and they pay you back with interest

When a municipality issues a bond, it is borrowing money from investors like you. You give them cash upfront. In return, they promise to pay you interest at regular intervals — usually twice a year — and return your principal on a set date, called the maturity date. That date might be 10, 20, or 30 years away. The interest rate is fixed when you buy the bond, so you know exactly what you will receive each payment period.

The municipality uses the money to pay for things it cannot cover with tax revenue alone: a new school building, a water treatment plant, a bridge repair, a highway expansion. They are not borrowing from a bank. They are borrowing from individual investors and institutions by selling bonds to the public.

You do not have to hold the bond until maturity. You can sell it to another investor before the maturity date, though the price you get depends on interest rates and the municipality's credit rating at the time you sell.

Key Takeaways

  • A municipal bond is a debt security where you lend money to a city, county, or state and receive fixed interest payments twice a year until the bond matures.
  • The municipality uses the borrowed money to fund public projects like schools, roads, water systems, and public buildings.
  • Most municipal bond interest is exempt from federal income tax, and often from state and local taxes too if you live in the issuing state.
  • You can sell a municipal bond before it matures, but the price fluctuates based on interest rates and the issuer's financial health.
  • Municipal bonds are generally considered lower-risk investments because they are backed by the taxing power of the government that issued them.

Why municipalities issue bonds instead of raising taxes

A city cannot simply print money or raise taxes overnight to build a new school. A bond lets them spread the cost across many years and many investors. The people who benefit from the school — current and future residents — help pay for it through the interest the municipality pays bondholders.

Bonds also allow a municipality to borrow large sums quickly. A $50 million school project might take decades to fund through annual tax increases, but a bond sale can raise that money in weeks. The municipality then repays the loan gradually, usually over 20 to 30 years, so the cost is distributed across many budget cycles.

How the interest payment works

When you buy a municipal bond, the issuer sets a coupon rate — the annual interest rate you will receive. If you buy a $5,000 bond with a 3% coupon, you receive $150 per year, usually split into two payments of $75 each, six months apart. This payment schedule does not change, even if interest rates in the broader economy rise or fall.

The coupon rate is determined by several factors: the current level of interest rates in the economy, the credit rating of the municipality, the length of time until the bond matures, and the type of bond (general obligation or revenue bond, explained below). A municipality with a strong credit rating can offer a lower coupon rate because investors see less risk. A weaker municipality must offer a higher rate to attract buyers.

General obligation bonds versus revenue bonds

A general obligation bond is backed by the full taxing power of the municipality. If the city needs to raise money to pay bondholders, it can increase property taxes, sales taxes, or other revenue sources. Because they are backed by the government's ability to tax, general obligation bonds are considered lower-risk and typically offer lower interest rates.

A revenue bond is backed only by the income from a specific project or service. A bond issued to build a toll road, for example, is repaid from toll revenue. A bond for a water treatment plant is repaid from water bills. If the project does not generate enough revenue, bondholders may not be paid in full. Because of this higher risk, revenue bonds typically offer higher interest rates than general obligation bonds from the same municipality.

The tax advantage of municipal bonds

The interest you earn on a municipal bond is usually exempt from federal income tax. If you buy a bond issued by your home state or certain local governments, the interest may also be exempt from state and local income taxes. This tax exemption is the main reason many investors choose municipal bonds over other fixed-income investments like corporate bonds or Treasury bonds.

The tax benefit is most valuable to investors in high tax brackets. If you are in the 24% federal tax bracket and earn $1,000 in municipal bond interest, you avoid $240 in federal taxes. A corporate bond paying the same $1,000 would cost you that $240. The effective return on the municipal bond is higher because you keep more of what you earn.

However, some municipal bonds are subject to the alternative minimum tax (AMT), a separate tax calculation that can affect high-income earners. Before buying a municipal bond, check whether it is AMT-taxable.

What happens when you sell before maturity

You do not have to hold a municipal bond until it matures. You can sell it on the secondary market — the market where existing bonds trade between investors — at any time. However, the price you receive depends on interest rates and the issuer's credit rating at the time of sale.

If interest rates have risen since you bought the bond, new bonds will offer higher coupon rates. Your older bond, with its lower rate, becomes less attractive, so you will have to sell it at a discount — below the price you paid. If interest rates have fallen, your bond becomes more valuable, and you can sell it at a premium — above the price you paid.

If the municipality's credit rating has declined, the bond becomes riskier and its price falls. If the rating has improved, the price rises. This is why municipal bond prices fluctuate, even though the coupon rate never changes.

Credit ratings and default risk

Before buying a municipal bond, check the issuer's credit rating. Agencies like Moody's, Standard & Poor's, and Fitch assign ratings based on the municipality's financial health, tax base, debt levels, and economic outlook. A rating of A or higher is generally considered investment-grade and relatively safe. Ratings below BBB are considered speculative or high-yield, meaning higher risk and higher potential return.

Municipal bond defaults are rare — most cities and states pay their debts — but they do happen. Detroit, Stockton, and Puerto Rico have all defaulted on bonds in recent decades. If a municipality defaults, you may not receive all of your interest payments or principal back. This is why credit rating matters: it reflects the real risk that the issuer might not be able to pay.

How to buy municipal bonds

You can buy municipal bonds through a broker, a bank, or directly from the issuer at a new bond offering. New issues are often sold through a municipal bond underwriter — a financial firm that helps the municipality sell the bonds to the public. You can also buy existing bonds on the secondary market through a broker.

Municipal bonds are typically sold in $5,000 increments, though some brokers allow smaller purchases. If you are buying through a broker, you will pay a commission or markup, though some brokers offer commission-free municipal bond trading. If you are buying at a new offering, there is usually no commission because the underwriter is paid by the municipality.

Frequently Asked Questions

What is the difference between a municipal bond and a Treasury bond?

Both are government debt, but a Treasury bond is issued by the federal government and backed by the full faith and credit of the United States. A municipal bond is issued by a city, county, or state. Treasury bonds are generally considered safer because the federal government has a larger tax base and stronger credit rating. However, municipal bond interest is usually tax-exempt, while Treasury interest is subject to federal tax, making the after-tax return on municipal bonds often higher for investors in high tax brackets.

Can I lose money on a municipal bond?

If you hold the bond to maturity and the issuer does not default, you will receive your full principal back plus all interest payments. However, if you sell before maturity and interest rates have risen or the issuer's credit rating has fallen, you will receive less than you paid. You can also lose money if the municipality defaults and cannot pay you back in full.

How long does it take to get paid after I buy a bond?

Interest payments are made on a schedule set when the bond is issued, usually twice a year on specific dates. The first payment you receive may be less than a full coupon payment if you buy the bond between payment dates, because you will receive accrued interest from the previous payment date. Your principal is returned on the maturity date.

Are municipal bonds a good investment for retirement accounts?

Municipal bonds are less useful in tax-advantaged retirement accounts like IRAs or 401(k)s because the tax exemption does not apply inside these accounts — the account itself is already tax-sheltered. You would be better off holding taxable bonds like Treasuries or corporate bonds in a retirement account and holding municipal bonds in a regular taxable account where you can benefit from the tax exemption.

What happens if a municipality goes bankrupt?

If a municipality files for bankruptcy, bondholders become creditors with a claim on the municipality's assets. General obligation bondholders typically have priority over other creditors because their bonds are backed by the municipality's taxing power. However, you may not receive your full principal or interest payments. The bankruptcy court will determine how much each creditor receives based on available funds and the priority of different claims.