Spin-Off Shares: Tax Treatment for Shareholders

In a tax-free spin-off, shareholders receive shares of a newly independent company without recognizing capital gain at the moment of distribution—but the IRS allocates their original cost basis across both the parent and spin-off shares, so future sales trigger capital gains tax based on the split basis.

What is a tax-free spin-off

A spin-off occurs when a parent company distributes shares of a subsidiary (or newly created entity) to shareholders, typically to separate two business lines. For example, Mondelez spun off Cadbury into an independent company, distributing Cadbury shares to Mondelez shareholders.

A tax-free spin-off (governed by Section 355 of the US Internal Revenue Code) means shareholders do not owe federal income tax when they receive the spin-off shares. The distribution is not treated as a dividend or other taxable event.

This is different from a taxable spin-off, where the company distributes cash or other property alongside the spin-off shares, or where the spin-off fails to meet IRS requirements. Taxable spin-offs are less common for major companies because they trigger shareholder-level gain recognition and are often structured to avoid it.

Most large corporate spin-offs (such as AT&T spinning off Warner Bros. Discovery, or Kraft Heinz spinning off Mondelez) are structured to qualify as tax-free under Section 355. The company obtains a private letter ruling from the IRS upfront to confirm tax-free status.

How cost basis is allocated

The critical insight is that tax-free does not mean basis-free. You do not get a step-up in basis; instead, your original basis in the parent stock is split between the parent and the new spin-off shares.

The allocation formula:

Allocated basis to spin-off = Original basis × (FMV of spin-off / (FMV of parent + FMV of spin-off))

Remaining basis in parent = Original basis × (FMV of parent / (FMV of parent + FMV of spin-off))

Where FMV = Fair Market Value on the spin-off date.

Example: You bought 100 shares of Parent Corporation for $5,000 (cost basis = $5,000 or $50/share). On the spin-off date, Parent is trading at $60/share and the newly spun-off subsidiary (NewCo) is trading at $40/share.

• FMV of your parent shares: 100 × $60 = $6,000
• FMV of your spin-off shares: 100 × $40 = $4,000
• Total FMV: $10,000

Your original $5,000 basis is split:

• Basis allocated to spin-off: $5,000 × ($4,000 / $10,000) = $2,000
• Remaining basis in parent: $5,000 × ($6,000 / $10,000) = $3,000

Now you hold:

• 100 Parent shares at $60/share with a basis of $3,000 (average basis $30/share).
• 100 NewCo shares at $40/share with a basis of $2,000 (average basis $20/share).

If you sell the Parent shares at $60, you recognize a gain of $6,000 − $3,000 = $3,000. If you sell NewCo shares at $40, you recognize a gain of $4,000 − $2,000 = $2,000.

Holding period for spin-off shares

The spin-off shares are treated as if you bought them on the same date you bought the original parent stock. This is called tacking the holding period.

If you held the parent stock for 1.5 years before the spin-off, the spin-off shares are also treated as held for 1.5 years at the moment of receipt. This matters for long-term vs. short-term capital gains treatment: if you sell the spin-off shares within 14 months of the parent purchase (even if only days after the spin-off distribution), the gain is short-term and taxed at ordinary income rates. If you sell after 12 months from the original parent purchase, the gain is long-term.

Tax reporting of spin-offs

The company (or your broker) reports the spin-off on Form 8937, which shows:

• The number of spin-off shares received.
• The FMV of the spin-off shares on the distribution date.
• The allocated basis to the spin-off shares.
• The allocated basis remaining in the parent stock.

You must attach Form 8937 to your tax return and adjust your cost-basis records accordingly. Your broker’s system usually updates automatically, but it’s wise to verify the basis allocation, especially if you owned the parent shares in multiple accounts or at different times.

When you later sell either the parent or spin-off shares, you report the transaction on Schedule D (Capital Gains and Losses). The gain or loss is calculated as selling price minus the allocated basis.

When a spin-off becomes taxable

A spin-off is taxable (meaning shareholders owe tax at distribution) if:

1. The company fails to meet Section 355 requirements. These include maintaining active business operations in the subsidiary, ensuring the parent retains 80%+ control before the spin-off, and ensuring the spin-off is not primarily tax-motivated.

2. The company distributes cash or other property with the spin-off. For example, if the parent distributes spin-off shares plus a special dividend, the dividend portion is taxable.

3. Shareholders receive boot (cash or securities not in proportion to their holdings). This is rare in standard spin-offs.

If a spin-off is taxable, shareholders recognize capital gain on the FMV of the spin-off shares at distribution (in excess of the basis allocated to them). This is uncommon for major corporate spin-offs because companies structure them to avoid it.

State and local tax treatment

Federal tax law treats a tax-free spin-off as nonrecognition event. State laws vary:

• Most states (including California, New York, and Texas) follow federal treatment and do not tax the distribution.
• Some states may have different corporate income tax or capital gains tax rules. For example, certain states might view a spin-off as an implicit realization of gain at the entity level, though this is rare for shareholders.
• Local taxes in cities or counties with stock transfer taxes or gains taxes may apply differently.

You should check your state’s tax authority or consult a local tax professional if you live in a high-tax state.

Wash-sale and related-party rules

If you sell the parent stock at a loss and buy spin-off shares derived from the same parent, wash-sale rules do NOT apply, because the spin-off is a distribution, not a purchase. The wash-sale rule applies only to sales and repurchases of substantially identical securities.

However, Section 355(f) rules may apply if you (or a related party) acquire shares of either the parent or subsidiary within 6 years after the spin-off. In rare cases, this can disqualify the spin-off’s tax-free status retroactively. This is extremely unlikely for shareholders receiving spin-off shares passively.

Strategic considerations

For long-term investors: Tax-free spin-offs are attractive because they defer taxation while allowing you to maintain exposure to both business lines separately. You can reallocate between parent and spin-off based on changing business prospects without triggering immediate tax.

For traders: Spin-off shares often trade at a discount in the first days after distribution (due to forced selling by index funds or tax-loss harvesting). If you believe the spin-off is undervalued, you can buy it; the allocated basis follows the market price at your purchase date, not the distribution date.

For tax-loss harvesting: You cannot realize a loss on the parent stock and immediately buy the spin-off shares (or vice versa) without triggering wash-sale rules, because they are separate securities.

See also