When a company you own stock in announces a spin-off, part of its business is being separated into a brand-new, independent public company, and you will automatically receive shares of that new company in your brokerage account. So what does a spin-off mean for shareholders in practical terms? You end up holding two stocks instead of one, usually without owing any tax on the distribution itself, but you do have to split your original cost basis between the two positions and keep an eye on a few situations that can turn the event taxable.
What Lands in Your Account
You don’t buy anything, sign anything, or fill out any forms. The parent company distributes shares of the new entity on a pro-rata basis, meaning every shareholder gets new shares in proportion to what they already own. A typical ratio might be one share of the new company for every five or ten shares of the parent. The board sets a record date, and anyone holding the parent stock on that date is entitled to the distribution.
The shares are delivered electronically through the Depository Trust Company, which routes them to brokerage accounts. On the distribution date, a new ticker symbol appears in your account alongside your existing parent position. From that moment on, you own two separate investments that trade independently, each with its own price, management, and board.
Before the official distribution, exchanges usually open a “when-issued” trading window where the new company’s stock trades on a conditional basis. During this period the parent trades in two parallel markets: a regular-way market where shares carry the right to receive the spin-off stock, and an ex-distribution market where they don’t. The NYSE generally begins when-issued trading three business days before the distribution date, and the ticker carries a “WI” suffix during the window. You don’t have to do anything during when-issued trading; it matters mostly if you’re buying or selling the parent stock in the days right before the split and want to know which version of the shares you’re getting.
Fractional Shares
Distribution ratios rarely divide cleanly. If you own 37 shares of the parent and the ratio is one-for-ten, you’re entitled to 3.7 shares of the new company. Most spin-offs handle the remainder by pooling the fractional pieces, selling them on the market, and sending you cash for your 0.7 share. That cash payment is generally treated as if you sold the fractional share, so you’ll recognize a small capital gain or loss on it even when the spin-off itself is tax-free.
Why the Distribution Is Usually Tax-Free
Under Section 355 of the Internal Revenue Code, a spin-off structured correctly does not trigger federal income tax for either the company or its shareholders. Companies plan for months, often years, around meeting the statute’s requirements, and by the time a deal reaches you it has almost always been engineered to qualify.
The requirements are strict. The parent has to distribute enough stock to give up “control” of the subsidiary, defined under Section 368(c) as at least 80 percent of the combined voting power and at least 80 percent of every other class of stock. Both the parent and the new company must be engaged in an active trade or business that has been conducted for at least five years ending on the distribution date. The transaction has to be motivated by a real corporate business purpose beyond tax savings. And it can’t be principally a “device” for distributing earnings and profits at capital gains rates rather than as ordinary dividends.
None of this is your paperwork to do. What matters for you is the outcome: if the deal qualifies, receiving the new shares is not a taxable event, and you don’t report income just because they showed up in your account.
Splitting Your Cost Basis
Even in a tax-free spin-off, you have to divide your original cost basis between the parent shares you keep and the new shares you receive. The allocation is based on the relative fair market values of the two stocks, typically measured by closing prices on the first regular trading day after the distribution.
The math is straightforward. Suppose you paid $100 per share for the parent stock. On the first trading day after the split, the parent closes at $85 and the new company closes at $15. The parent represents 85 percent of the combined value, so your basis in the parent becomes $85 per share and your basis in the new company shares is $15 per share. The parent company usually publishes an official allocation percentage in a shareholder tax information document, and that is the figure you should use on your return. Save it. You’ll need those numbers to calculate gain or loss whenever you eventually sell either stock, which could be many years later.
Your holding period carries over as well. The new shares are treated as held for the same length of time as the original parent shares. If you held the parent for three years before the spin-off, the new shares are automatically considered held for three years too, which matters for qualifying for long-term capital gains rates when you sell.
When You Actually Owe Tax
A few situations can produce a real tax bill.
The cash you receive in lieu of a fractional share is taxable. It’s small, but it belongs on your return as a capital gain or loss depending on how the fractional share’s allocated basis compares to the cash amount.
When you eventually sell either stock, you use the split basis figures to calculate gain or loss, at long-term or short-term rates based on the carried-over holding period.
And a spin-off can fail to qualify under Section 355. It’s rare because companies plan carefully to avoid this outcome, but it happens. If the transaction doesn’t meet the statutory requirements, the distribution is treated as a taxable dividend to the extent of the parent’s earnings and profits, or as a capital gain if those earnings and profits have been exhausted. For most individual shareholders, long-term capital gains rates apply: 0 percent, 15 percent, or 20 percent depending on income. For tax year 2025, the 20 percent rate kicks in above $533,400 for single filers and $600,050 for married couples filing jointly. High-income shareholders may also owe the 3.8 percent net investment income tax on top of that, which applies to individuals with modified adjusted gross income above $200,000 (single) or $250,000 (married filing jointly).
There is also a delayed tripwire the parent company watches, and it can indirectly affect shareholders if triggered. Under Section 355(e), sometimes called the anti-stuffing rule, a qualifying spin-off can lose its tax-free status at the corporate level if 50 percent or more of either company is acquired within a window running from two years before to two years after the distribution. The rule presumes such an acquisition is part of a plan, and the burden is on the companies to prove otherwise. If it’s triggered, the parent recognizes corporate-level gain on the distribution, though the shareholder-level treatment of the original distribution generally still stands.
Holding, Selling, or Reviewing What You Received
Once the new shares arrive, you are under no obligation to hold both. Some shareholders keep both companies because they liked the pre-spin business as a whole. Others sell the one they didn’t want exposure to and concentrate in the other. Both are ordinary transactions once the shares are in your account, taxed at capital gains rates based on your split basis and carried-over holding period.
If you want to understand exactly what each company now owns and owes before you decide, the separation and distribution agreement is filed with the SEC as an exhibit to the new company’s Form 10 registration statement or a proxy statement. It spells out which assets, liabilities, and litigation risks went where. One item worth knowing about: under Treasury regulations, both the parent and any subsidiary that was part of the parent’s consolidated tax group remain jointly liable for the group’s consolidated federal income tax for any year they were affiliated, so pre-separation tax exposure can follow either company regardless of how the private agreement between them assigns it.
For most shareholders, the practical to-do list after a spin-off is short: confirm the new shares posted correctly, record the official basis allocation percentage the parent publishes, note the cash received for any fractional share on next year’s return, and decide whether the two-stock position still matches what you want to own.