Tax Treatment of Municipal Securities

Tax treatment drives the pricing and yield calculations for municipal bonds. Understanding exactly what is and is not tax-exempt is essential for the exam.


Federal Income Tax Status

  • Interest on governmental purpose municipal bonds is exempt from federal income tax
  • Interest on private activity bonds subject to the alternative minimum tax (AMT) is a tax preference item
  • Taxable municipal bonds (e.g., Build America Bonds, certain private activity bonds) pay interest that is fully taxable at the federal level

State and Local Tax Status

ScenarioTax Treatment
Bond from investor's home stateTypically triple tax-free (federal + state + local)
Bond from another stateFederal exempt, but subject to investor's state income tax
U.S. territory bonds (Puerto Rico, Guam, USVI)Triple tax-exempt for investors in all states

Exam Tip: Gotchas

  • U.S. territory bonds (Puerto Rico, Guam, USVI) are triple tax-exempt for ALL investors regardless of state. This makes them uniquely attractive for tax-sensitive investors in any state.

Premium Bonds (Purchased in Secondary Market)

  • The premium must be amortized over the remaining life
  • Amortization reduces cost basis annually
  • The amortized premium is not deductible (because the income is tax-exempt)
  • At maturity, cost basis = par; no capital gain or loss

Think of it this way: If you pay $1,050 for a $1,000 par bond with 10 years left, you amortize $5 per year. Each year your cost basis drops by $5. At maturity, your basis equals par ($1,000), so there is no gain or loss. And because the interest is tax-exempt, you cannot deduct the premium either.

Exam Tip: Gotchas

  • Premium amortization on munis is NOT deductible. You cannot take a tax loss on amortizing a tax-exempt bond. The tax-free interest is the tradeoff.

Market Discount Bonds (Purchased in Secondary Market)

  • If a bond is purchased below par in the secondary market, the market discount is the difference between par and the purchase price
  • At sale or maturity, the accrued market discount is taxed as ordinary income (not capital gain)
  • The investor may elect to accrete the discount annually or recognize it all at disposition

Original Issue Discount (OID)

  • For tax-exempt municipal OID bonds, the accretion is treated as tax-exempt interest income (not taxable)
  • The bondholder's cost basis increases by the annual accretion amount
  • If sold before maturity at a price above the accreted value, the excess is a capital gain

OID vs. market discount:

OID (Issued Below Par)Market Discount (Bought Below Par in Secondary Market)
Tax treatment of accretionTax-exempt interestTaxable ordinary income
Cost basisIncreases annuallyMay increase if electing annual accretion
Who created the discountThe issuer (sold below par at issuance)The market (price fell after issuance)

Exam Tip: Gotchas

  • OID accretion on munis is tax-exempt; market discount accretion is taxable ordinary income. The key distinction is who created the discount: the issuer (OID, tax-exempt) vs. the market (market discount, taxable).

Accrued Interest

  • Accrued interest received by the seller is tax-exempt (same as regular interest)
  • Accrued interest paid by the buyer is treated as a return of tax-exempt income when the buyer receives the next coupon (not separately taxable)

Alternative Minimum Tax (AMT)

  • Interest on private activity bonds (bonds where more than 10% of proceeds benefit a private entity) is a preference item for AMT
  • Governmental bonds and 501(c)(3) bonds (issued for nonprofits) are NOT subject to AMT
  • Private activity bonds include: industrial development revenue bonds, certain airport bonds, student loan bonds, housing bonds
  • AMT bonds carry higher yields to compensate for the tax treatment

Exam Tip: Gotchas

  • AMT applies to private activity bonds, NOT to governmental bonds or 501(c)(3) bonds. If the exam asks which muni bonds are subject to AMT, only private activity bonds qualify.

Bank-Qualified Bonds

  • Municipal bonds issued by small issuers (no more than $10 million in tax-exempt bonds per calendar year) may be designated as bank-qualified (or "qualified tax-exempt obligations")
  • Banks that purchase bank-qualified bonds may deduct 80% of the carrying cost (interest expense) of funds used to buy the bonds
  • This makes bank-qualified bonds attractive to commercial banks, increasing demand and lowering borrowing costs for the issuer

Exam Tip: Gotchas

  • Bank-qualified threshold: $10 million per calendar year. The 80% carrying cost deduction applies only to banks, not individual investors.

Capital Gains on Municipal Bonds

  • If a bond is sold for more than its adjusted basis, the gain is a capital gain (taxable)
  • Capital gains on municipal bonds are NOT tax-exempt (only the interest is exempt)
  • Short-term capital gain (held 1 year or less): taxed as ordinary income
  • Long-term capital gain (held more than 1 year): taxed at preferential capital gains rates

Exam Tip: Gotchas

  • Municipal bond interest is tax-exempt, but capital gains are NOT. If you buy a muni at 90 and sell at 95, the $50 per bond gain is a taxable capital gain.
  • Market discount is taxed as ordinary income (not capital gains). This is a frequent exam trap.