Bond Premium Amortization Tax Treatment

Investors who purchase a taxable bond at a bond premium amortization can elect to deduct a portion of the premium against interest income each year, reducing annual ordinary income and converting some of the premium into a capital loss at maturity.

The Premium Problem

When an investor buys a bond at a price above its par (face) value — say, paying $1,050 for a $1,000 bond — the difference is premium. Premium arises when a bond’s coupon rate exceeds current market interest rates. A bond with a 5% coupon is worth more than par if market rates fall to 3%.

Without special tax treatment, the investor would face an economic distortion:

• Annually, the investor receives full coupon payments (based on par value) and reports the full amount as taxable interest income
• At maturity, the investor receives only par value ($1,000) — a $50 loss compared to the $1,050 purchase price
• The $50 premium is treated as a capital loss, which is less valuable than an ordinary deduction

Result: the investor pays ordinary income tax on more interest than economic reality warrants, then claims a capital loss (which is limited to $3,000 per year against ordinary income).

Congress created the premium amortization election to address this mismatch.

How Premium Amortization Works

Under the election, the investor recognizes a portion of the premium as a deduction against interest income each year. The deduction is calculated using the constant yield method (or straight-line, if simpler and not material).

Constant yield method: The premium is amortized so that each year’s deduction is calculated as the difference between the coupon payment and the interest accrual based on the bond’s constant (yield-to-maturity) rate applied to the bond’s adjusted basis.

Example:

• Purchase price: $1,050
• Par value: $1,000
• Coupon rate: 5% (annual coupon = $50)
• Remaining term to maturity: 5 years
• Yield to maturity at purchase: 3.81%

In Year 1, the adjusted basis is $1,050. Interest accrual at 3.81% is approximately $40. Coupon received is $50. The excess, $10, is premium amortization — a deduction against interest income.

In Year 2, the adjusted basis is now $1,040 ($1,050 - $10). Interest accrual is about $40, coupon is $50, so the deduction is again about $10.

By maturity, the total premium amortized ($50) reduces basis to par ($1,000). The investor receives $1,000 and recognizes no capital gain or loss.

Without the election, the investor would claim a $50 capital loss at maturity — much less valuable than five $10 ordinary deductions.

Taxable Bonds vs. Tax-Exempt Bonds

The premium amortization election applies only to taxable bonds. Tax-exempt bonds (municipal bonds) have mandatory amortization, meaning the premium is always deducted against interest income — the election is required, not optional.

For taxable bonds, the election is optional and must be affirmatively made on the tax return (typically Form 8949 or within tax software).

Making the Election

To elect premium amortization for a taxable bond, the investor:

1. Completes Form 8949 (Sale of Capital Assets) or uses tax preparation software that supports the election
2. Calculates the premium amortization using the constant yield method (or straight-line)
3. Reports the amortized portion as a deduction against interest income (reported on Schedule B or in “Interest Income” section)
4. Does not report the premium as a separate capital loss

The election is irrevocable once filed. If an investor elects amortization for a bond in Year 1, the investor cannot switch back to treating the entire premium as a capital loss in a later year.

Benefits and Trade-Offs

Benefits of electing amortization:

• Converts a portion of premium into ordinary deductions, which are more valuable than capital losses for most investors
• Spreads the benefit across multiple years rather than lumping it into a capital loss at maturity
• Reduces net interest income reported annually, lowering taxable income in each year of holding

Trade-offs:

• Reduces the adjusted basis of the bond, so if the bond is sold before maturity, the capital gain may be larger (or capital loss smaller)
• Eliminates the capital loss at maturity, so if the investor wanted to harvest a loss for other gains, the election is disadvantageous
• Requires accurate record-keeping of adjusted basis and amortization across multiple tax years

Timing and Maturity Scenarios

Premium amortization is most valuable when:

• The investor intends to hold the bond to maturity (so the final adjusted basis of par is locked in)
• The investor’s ordinary income tax rate exceeds the capital gains rate (since the deduction applies to ordinary income)
• The bond has multiple years to maturity (spreading the deduction across years)

Premium amortization is less valuable when:

• The investor plans to sell the bond before maturity (the adjusted basis reduction increases capital gains on sale)
• The investor has substantial capital losses already and wants to use the premium loss to offset capital gains in a specific year

Example Calculation

Bond purchased for $1,050, par $1,000, 5% coupon (annual $50 payment), 5 years to maturity, YTM 3.81%:

Each year, the investor deducts the premium amortization against interest income. At maturity, the investor receives $1,000 and has no capital loss.

Interaction With Capital Losses and Harvesting

If an investor holds multiple bonds and some have unrealized losses, the premium amortization election on premium bonds affects tax-loss harvesting strategy. Selling a premium bond after electing amortization creates a smaller capital loss (because basis has been reduced by amortization). By contrast, if the election had not been made, the premium could be claimed as a capital loss at maturity.

An investor might deliberately avoid the amortization election if planning to sell the bond at a loss and use that loss to offset unrelated capital gains.

See also