Municipal Bonds

Municipal bonds are issued by state and local governments (cities, counties, school districts, public authorities). Their primary advantage is tax-exempt interest.


Types of Municipal Bonds

TypeBackingSecurity
General Obligation (GO)Full faith and credit of issuerAd valorem (property) taxes
Revenue BondSpecific project revenuesTolls, user fees, lease payments

GO Bond Characteristics

  • Backed by the full faith, credit, and taxing power of the issuing municipality
  • Repaid from ad valorem (property) taxes and general tax revenues
  • Typically require voter approval
  • Considered safer than revenue bonds from the same issuer

Revenue Bond Characteristics

  • Backed by revenue from a specific project or facility (toll road, hospital, airport, utility)
  • No taxing power backing; if the project fails to generate revenue, bondholders may not be paid
  • Do not require voter approval
  • Include a feasibility study before issuance
  • Typically offer higher yields than GO bonds from the same issuer (more risk)
  • Protected by a rate covenant (issuer must maintain user fees/rates sufficient to cover debt service)

GO vs. Revenue Bonds Comparison

FeatureGO BondsRevenue Bonds
BackingTaxing power (ad valorem)Specific project revenue
Voter approvalUsually requiredNot required
RiskLowerHigher
YieldLowerHigher
Key covenantDebt limitRate covenant

Other Municipal Securities

Industrial Development Revenue Bonds (IDRBs): Issued by municipalities to finance private facilities. Backed by the private corporation (not the municipality). May be subject to Alternative Minimum Tax (AMT).

Short-term municipal notes: Used to bridge temporary cash flow gaps:

  • TANs (Tax Anticipation Notes) - repaid from expected tax receipts
  • RANs (Revenue Anticipation Notes) - repaid from expected revenues
  • BANs (Bond Anticipation Notes) - repaid from proceeds of a future bond issue

Exam Tip: Gotchas

  • IDRBs are backed by the corporation's credit, not the municipality. The city is just a conduit issuer. Municipal bond interest may be subject to AMT if issued as a private activity bond.

Insured Municipal Bonds

  • Backed by a third-party insurance company that guarantees timely payment of principal and interest
  • Insurance raises the bond's credit rating (typically to AAA)
  • Insured bonds trade at lower yields than uninsured bonds of the same issuer
  • Insurance does not protect against market/interest rate risk; only credit risk

Think of it this way: Bond insurance transfers credit risk to the insurer. Even if the municipality struggles financially, the insurance company guarantees payment. The trade-off is a lower yield.

Exam Tip: Gotchas

  • Insured municipal bonds protect against credit risk only, not interest rate risk. They carry the insurer's rating, typically AAA.

Tax Treatment

  • Interest is generally exempt from federal income tax
  • May be double-exempt (federal + state) if investor resides in the issuing state
  • May be triple-exempt (federal + state + city) in certain jurisdictions (e.g., New York City)
  • Capital gains on municipal bonds are taxable (only interest is tax-exempt)

Exam Tip: Gotchas

  • Municipal bond interest is tax-exempt, but capital gains are fully taxable. GO bonds are backed by taxing power and need voter approval; revenue bonds are backed by project revenue and do NOT need voter approval.

Tax Equivalent Yield (TEY)

To compare municipal bonds to taxable bonds:

TEY=Municipal Bond Yield1Tax Bracket\text{TEY} = \frac{\text{Municipal Bond Yield}}{1 - \text{Tax Bracket}}

Example: 4.2% municipal, investor in 40% bracket:

  • TEY = 4.2% ÷ (1 - 0.40) = 4.2% ÷ 0.60 = 7.0%
  • The investor would need a 7% taxable bond to equal the 4.2% municipal after taxes

Reverse Calculation: What tax-free yield equals a taxable yield?

  • Taxable yield × (1 - Tax bracket) = Tax-free equivalent
  • 8% × (1 - 0.30) = 8% × 0.70 = 5.6%

Exam Tip: Gotchas

  • The higher your tax bracket, the more valuable tax-exempt income becomes. A 4% muni equals a 7% taxable bond for someone in the 43% bracket, but only a 5.3% equivalent for someone in the 25% bracket.