Form 8937, Report of Organizational Actions Affecting Basis of Securities, is filed by the issuer of a stock, bond or other security when a corporate action changes the cost basis investors hold, such as a stock split or a nontaxable cash distribution. It's due 45 days after the action, or by 15 January of the following year if that's earlier, and most large issuers simply post it on their investor relations website instead of filing it with the IRS.
This is based on Form 8937 and its instructions (Rev. December 2017), still the current revision as of October 2026.
Why investors search for Form 8937
If you're an investor, you'll almost never file this form. You'll look one up, because it tells you how a corporate action changed the basis of your shares. Basis is what your gain or loss is measured against when you sell. Part II, line 15, is the line that matters most to you: it states the effect on basis per share or as a percentage of old basis.
Who must file
An issuer of a specified security files when it takes an organizational action that affects the basis of that security. Specified securities include:
- shares of stock in a corporation, including interests treated as stock such as American Depositary Receipts
- options, warrants and stock rights
- securities futures contracts
- debt instruments, apart from a few excluded types
The rule applies to foreign issuers too, when US taxpayers own the security directly or through depositary receipts.
Actions that need one, and actions that don't
| Needs Form 8937 | Doesn't need Form 8937 |
|---|---|
| A nontaxable cash distribution to shareholders | A distribution reportable as a dividend on Form 1099-DIV |
| A nontaxable stock distribution, including a stock split | An initial public offering |
| A conversion rate adjustment on convertible debt treated as a distribution | A new debt issue, unless it's part of a recapitalization |
| Debt issued in a recapitalization, a significant modification or a bankruptcy reorganization | Stock issued to someone exercising a right to buy it |
The public website shortcut
An issuer doesn't have to file with the IRS if, by the due date, it posts a completed, signed Form 8937 on its primary public website in an area set aside for this, and keeps it there for 10 years. Posting it also counts as giving a copy to every holder and nominee. That's why the quickest way to find one is the company's investor relations or tax information page.
Deadlines
- File with the IRS, or post publicly, by the 45th day after the action, or 15 January of the next year if earlier.
- Give holders an issuer statement by 15 January of the year after the action.
- If later facts change the effect on basis, file a corrected return within 45 days of finding out, and give holders a corrected statement by the later of 15 January or 45 days after determining the facts.
The issuer can make reasonable assumptions to meet the deadline when some facts aren't known yet. For a redemption, the action is treated as happening on the last day a holder may redeem.
Special rules worth knowing
- No reporting is needed if every holder is an exempt recipient, such as C corporations, charities, foreign holders, IRAs and HSAs.
- An S corporation that reports the effect on a timely Schedule K-1 to every shareholder doesn't need Form 8937.
- A fund or REIT that reports undistributed gains on Form 2439 meets the requirement for those gains that way.
- An acquiring or successor company must report if the original issuer didn't, and both can be liable for penalties.
What the issuer writes in Part II
| Line | What it asks |
|---|---|
| 14 | A description of the action and its date, or the date ownership is measured against |
| 15 | The effect on basis per share, or as a percentage of old basis |
| 16 | How the change was calculated, including market values and valuation dates |
| 17 | The tax code sections the treatment relies on |
| 18 | Whether any resulting loss can be recognized |
| 19 | Any other information, such as the reportable tax year |
Part I covers the issuer's name and EIN, a contact person with phone and email, and identifiers such as the CUSIP number and ticker symbol, which is how you match the form to the security in your account.
Using a Form 8937 as an investor
Find the form for the action, read line 14 to confirm which event it covers, then apply line 15 to your own cost per share. Line 18 says whether any loss can be recognized, and line 19 notes the reportable tax year. Compare the result with your broker's basis figures on Form 8949 and Schedule D, and keep a copy of the form with your purchase records.
The verdict
Form 8937 is a short, two-page form that does one job well: it tells you how much of your original investment a corporate action moved, returned or reshaped. If your broker's basis looks wrong after a split or a nontaxable distribution, the issuer's Form 8937 is the document that settles it.
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Frequently asked questions
What is Form 8937?
It's the Report of Organizational Actions Affecting Basis of Securities that an issuer files when an action such as a stock split or nontaxable distribution changes holders' basis.
When is Form 8937 due?
On or before the 45th day after the organizational action or, if earlier, 15 January of the year following the action.
Do companies have to file Form 8937 with the IRS?
Not if they post a completed, signed Form 8937 on their primary public website by the due date and keep it there for 10 years.
Do I need to file Form 8937 as a shareholder?
No. It's filed by the issuer; shareholders use it to adjust the basis of their shares.
Where do I find a company's Form 8937?
Usually on the investor relations or tax information area of the company's website, since posting it there counts as giving it to holders.
Does a stock split need a Form 8937?
Yes. The instructions give a nontaxable stock distribution, including a stock split, as an example of an action that requires Form 8937.
What if the issuer gets the basis figure wrong on Form 8937?
It must file a corrected return within 45 days of determining the facts that change the effect on basis, and give holders a corrected statement.
