Form 1099-OID: Market Discount vs Original Issue Discount Explained

Bonds are sold at par, at a discount, or at a premium. When a bond is issued at a discount—meaning investors pay less than its face value—the difference is Original Issue Discount (OID), which accrues and is taxable as interest income over the bond’s life. If you buy that same bond later at an even deeper discount, the additional markdown is market discount, which has its own reporting rules. Form 1099-OID distinguishes these two income streams and tells you which goes where on your Schedule B.

Original Issue Discount: the discount embedded at creation

Original Issue Discount occurs when the bond issuer sells a bond for less than its par value at the time of first issuance. A $1,000 par bond sold to the first investors for $950 has $50 OID. The investor will receive $1,000 at maturity, netting a $50 gain, but that gain isn’t a one-time event at maturity—it accrues ratably (or using the constant-yield method) over the bond’s life.

OID is typically seen in:

• Zero-coupon bonds (no coupon payments; the entire return is the difference between purchase and par).
• Original-issue bonds with extremely low or zero coupon rates.
• Certain corporate bonds issued in distressed conditions.
• U.S. Treasury STRIPS (Separate Trading of Registered Interest and Principal of Securities).

If you own an original-issue zero-coupon bond, you owe tax on the accrued OID each year even though you receive no cash until maturity. This is why zero-coupon bonds are often held in tax-deferred accounts (IRAs, 401(k)s)—the annual phantom income would otherwise be burdensome in taxable accounts.

Market Discount: the discount you get when buying secondary

Market discount is a different animal. It arises when you purchase a bond in the secondary market (from another investor) at a price below the bond’s accreted value.

Example: A $1,000 par bond was originally issued with $50 OID. Three years later, the issuer’s credit quality deteriorates and interest rates rise. You buy the bond in the secondary market for $800. The bond’s accreted value at that point is, say, $925. You’ve purchased it $125 below par. That $125 is market discount—additional to the original $50 OID.

Market discount is taxable, but only when you sell the bond or it matures. You don’t accrue it annually like OID. Instead, you defer the entire market-discount gain until the bond disposition.

The IRS offers an election (Form 1099-OID Part III) to include market discount ratably in income each year, similar to OID inclusion. Few investors make this election, because deferring tax to the exit year is usually more valuable.

How OID is calculated and accrued

The constant-yield method is the IRS standard for OID accrual. Rather than a straight-line division of OID across years, the method uses the bond’s yield to maturity and compounds interest, reflecting the fact that OID accrues at an increasing rate as maturity approaches.

For a Treasury STRIP with $950 purchase price and $1,000 par due in 10 years, the annual yield is roughly 0.525%. Year one accrual is $950 × 0.525% ≈ $5. Year two accrual is ($950 + $5) × 0.525% ≈ $5.03. The accrual grows slightly each year.

Form 1099-OID Part I reports the accrued OID for the tax year. If you own a Treasury STRIP through a brokerage, they’ll send you a Form 1099-OID in January showing the amount you must include in income that year. You report it on Schedule B.

Market discount election and deferral

Market discount can be taxed in two ways:

1. Deferral (default): You recognize the entire market-discount gain when you sell the bond. If you bought at $800 and sell at $950, you report $150 gain as either long-term or short-term depending on holding period. This gain is capital gain, not ordinary income.

2. Current inclusion (election): You include market discount ratably in income each year. If the bond has five years to maturity and $125 in market discount, you include $25 in ordinary income each year. At maturity or sale, you adjust your basis upward for amounts already included, eliminating the deduction when you eventually receive par or sell.

The election is made on Form 1099-OID or your return (there’s no separate form). Once made for a bond, it cannot be revoked without IRS permission.

Most investors default to deferral because it pushes the tax event to the exit year and treats the gain as capital gain (lower rates). Current inclusion is sometimes chosen in the year of purchase if the investor knows they’ll hold long-term and wants to smooth ordinary income across years.

Interaction between OID and market discount on the same bond

Confusion arises when the same bond carries both OID (from its original issuance) and you add market discount (by buying it at a further discount). Form 1099-OID shows both.

An original-issue $1,000 par Treasury STRIP with $50 OID is purchased by you in the secondary market at $800. You have:

• $50 OID accruing over the remaining bond life (original discount).
• $150 market discount ($950 accreted value minus your $800 purchase = $150 additional discount you received).

Form 1099-OID Part I reports the OID accrual for the year you own it. Part II reports your market-discount position and may indicate whether you’ve elected current inclusion. You accrue the OID annually and defer (or elect to include) the market discount separately.

Reporting on Schedule B and the tax treatment distinction

OID is always ordinary income reported on Schedule B (Interest and Dividend Income). Market discount, if deferred, is capital gain on Schedule D at your longterm or shortterm rate. If you elect current inclusion of market discount, it becomes ordinary income also reported on Schedule B.

The distinction matters. High-income investors in the 37% marginal bracket get a much better deal deferring market discount (15% or 20% long-term capital-gain rate) than electing current inclusion (37% ordinary rate).

Brokerage statements and Forms 1099-OID can be hard to parse. Many investors misread the code boxes and report market discount as ordinary income when it should be capital gain, or vice versa. Reconciling the 1099-OID with your bond lot records (cost, par, date purchased) prevents this error.

Bonds bought at a premium and negative OID

When a bond is issued above par (premium), the difference is negative OID. You amortize it over the bond’s life, reducing your basis. At maturity, you recognize a loss equal to any remaining unamortized premium, unless you’ve made an election to fully amortize the premium (which is done on Form 4982).

Premium bonds are less common in the issuance phase (bonds are usually issued near par unless the coupon is unusually high), but you can certainly buy bonds at a premium in the secondary market if rates have fallen since issuance.

Negative OID doesn’t appear on Form 1099-OID in the traditional sense; instead, the brokerage reports the premium-amortization amount, and you track it for basis adjustment.

Stripped bonds and TreasurySTRIPS

Treasury STRIPS—zero-coupon securities created by separating a Treasury bond’s principal and interest payments—are entirely OID-based. You buy them at a steep discount (often 40–60% of par) and receive nothing until maturity. All the gain is OID, accrued annually and reported on Form 1099-OID.

The phantom-income problem is severe: a 10-year Treasury STRIP bought at $500 requires you to include roughly $30–40 per year in income, yet you receive no cash. Only suitable for tax-deferred accounts or investors with sufficient other income to absorb the tax.

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