The wash sale rule applies to RSUs the same way it applies to any other stock: if you sell vested shares of your company’s stock at a loss and acquire more of the same stock within the 30 days before or after the sale, the IRS disallows the loss.1Office of the Law Revision Counsel. 26 USC 1091 – Loss From Wash Sales of Stock or Securities For RSU holders the trap is almost structural. Scheduled vestings you don’t control, ESPP purchases, 401(k) contributions directed to company stock, dividend reinvestments, and even a spouse’s purchases all count as replacement acquisitions. When the replacement shares land in an IRA or 401(k), the loss isn’t just deferred to a later sale. It disappears.
How a Loss on RSU Shares Arises in the First Place
RSUs are taxed as ordinary income when the shares are delivered to you. The fair market value on the delivery date hits your W-2, and that same value becomes your cost basis in the shares.2Charles Schwab. Restricted Stock and Performance Stock Taxes: A Guide If the stock drops after vesting and you sell, the difference between your sale price and that vest-date basis is a capital loss. That loss is what the wash sale rule can take away.
The 61-Day Window and What Counts as an Acquisition
Under 26 U.S.C. § 1091, a loss is disallowed if you acquire substantially identical stock within a 61-day window: the 30 days before the sale, the sale date, and the 30 days after.1Office of the Law Revision Counsel. 26 USC 1091 – Loss From Wash Sales of Stock or Securities The rule also reaches contracts and options to acquire the stock.
For an employee selling RSU shares, “substantially identical” is not ambiguous. Your company’s common stock is substantially identical to more of your company’s common stock, no matter which account holds it or how it got there. The usual outcome is that the disallowed loss gets added to the cost basis of the replacement shares, and the original holding period carries over.3Internal Revenue Service. Publication 550 – Investment Income and Expenses One major exception breaks that recovery, covered below.
Why RSU Holders Trigger Wash Sales Without Trying
The rule was written to stop investors from selling to harvest a loss and immediately buying back. RSU holders have no such intent, but a typical four-year schedule with quarterly releases delivers new shares eight to sixteen times a year, and each delivery is an acquisition under § 1091. Sell at a loss and the next vest within 30 days replaces what you sold.
Scheduled RSU Vests
Quarterly vesting means a new acquisition every roughly 90 days. Monthly vesting makes a clean loss sale nearly impossible without a long pause.
ESPP Purchases
Employee Stock Purchase Plans buy company shares on your behalf at the end of each offering period. A loss sale within 30 days of that purchase date triggers the rule, and the ESPP sitting in a separate account doesn’t change the outcome.
401(k) Contributions to Company Stock
If your 401(k) offers company stock as an investment option, or your employer matches in company stock, each payroll-period purchase is an acquisition. Those purchases can disallow a loss you took in your brokerage account on the same stock.
Dividend Reinvestment
A DRIP quietly buys more shares every dividend payment. A $50 reinvestment can disallow a much larger loss.
Spousal Purchases
The rule reaches your spouse’s acquisitions during the 61-day window.3Internal Revenue Service. Publication 550 – Investment Income and Expenses If you both work for the same company and both receive RSUs, one spouse’s vest can wipe out the other spouse’s loss.
The Retirement Account Trap
This is the single most expensive mistake RSU holders make. The usual rule, that the disallowed loss gets added to the basis of the replacement shares so you recover it on a later sale, does not apply when the replacement is acquired inside an IRA or Roth IRA. The IRS stated this directly in Revenue Ruling 2008-5,4Internal Revenue Service. Rev. Rul. 2008-5 – Losses From Wash Sales of Stock or Securities and Publication 550 confirms the carve-out: you add the disallowed loss to the cost of the replacement shares except when the replacement was acquired for your IRA or Roth IRA.3Internal Revenue Service. Publication 550 – Investment Income and Expenses
Because cost basis isn’t tracked share-by-share inside an IRA, there is no mechanism to recover the deferred loss later. A $5,000 loss disallowed because your IRA bought the same stock within 30 days is destroyed, not deferred.
Revenue Ruling 2008-5 named IRAs and Roth IRAs specifically. The IRS has not issued equivalent guidance for 401(k) plans, but the same practical problem exists: there is no standard way to adjust the basis of shares held inside a 401(k). Many tax professionals treat 401(k) replacement purchases the same way. If your 401(k) is buying company stock through regular contributions, assume any loss those purchases disallow will not come back to you.
How Much of the Loss Is Disallowed
When replacement shares equal or exceed the number you sold at a loss, the entire loss is disallowed. When replacements are fewer, only a proportional piece is disallowed.1Office of the Law Revision Counsel. 26 USC 1091 – Loss From Wash Sales of Stock or Securities
Say you sell 100 RSU shares at $90 each. Your vest-date basis was $100 per share, so you realize a $1,000 loss. Two weeks later your ESPP buys 50 shares at $85.
Half the loss, $500, is disallowed because 50 of the 100 sold shares were replaced. The other $500 remains deductible. The $500 disallowed amount is added to the basis of the 50 ESPP shares, which had an original basis of $4,250 and now carry an adjusted basis of $4,750.5IRS Link and Learn Taxes. Case Study 1 – Wash Sales The holding period of the sold shares also tacks onto the replacements, preserving your progress toward long-term capital gains treatment.6Office of the Law Revision Counsel. 26 US Code 1223 – Holding Period of Property
The December-January Trap
The 61-day window ignores the calendar year. Sell on December 15, acquire on January 4, and the loss is disallowed on the earlier year’s return even though the triggering purchase happened in the next tax year.
For RSU holders on quarterly vesting, the math is unforgiving. A January 1 vest reaches back to December 2. Any loss sale after December 2 gets caught. Running the other direction, a December 10 ESPP purchase reaches forward to January 9, so a loss sale anytime between November 10 and January 9 is disallowed by that single buy.
How to Avoid Triggering a Wash Sale on RSU Shares
You can’t stop RSUs from vesting, but you can control the sale timing and the enrollment choices that create extra acquisitions.
- Map your acquisition calendar. List every date company stock will land in any account: vest dates, ESPP purchase dates, 401(k) contribution dates, dividend payment dates. A planned loss sale needs to sit outside the 61-day window around each one.
- Pause DRIP at least 31 days before a planned loss sale. One small reinvestment can disallow a much larger loss.
- Redirect 401(k) contributions out of company stock at least 31 days before selling, and resume after the 30-day post-sale window closes. The IRS has not confirmed a basis recovery mechanism inside a 401(k), so treat these purchases as capable of destroying the loss.
- Coordinate with your spouse. Their RSU vests, ESPP purchases, and open-market buys of the same stock are your wash sale triggers too.
- Wait 31 days. The simplest option. The cost is price risk while you sit out.
One strategy that works for individual stocks does not help with RSUs: buying a similar but not identical security to stay invested. Stocks of different companies are generally not substantially identical, so you can sell your company stock and buy a sector ETF to maintain exposure during the waiting period.3Internal Revenue Service. Publication 550 – Investment Income and Expenses That doesn’t solve the core problem. You still can’t stop the next vest from delivering shares of the exact stock you just sold.
Reporting the Wash Sale
Wash sales are reported on Form 8949, with totals flowing to Schedule D.7Internal Revenue Service. About Form 8949, Sales and Other Dispositions of Capital Assets Your broker issues a 1099-B showing proceeds and basis and may flag the wash sale, but brokers only see transactions in their own accounts. If the replacement happened at a different brokerage, in your 401(k), or in your spouse’s account, the 1099-B will not catch it. You will.
On Form 8949, enter the proceeds and basis in the usual columns, then enter code “W” in the adjustment code column and the nondeductible loss as a positive number in the adjustment column. That zeros out or reduces the loss on that line.8Internal Revenue Service. Instructions for Form 8949
Then track the adjusted basis of the replacement shares. When those shares are sold months or years later, their basis must include the disallowed loss from the earlier wash sale. Lose that record and you’ll either overstate the eventual gain or lose the deferred loss altogether. A spreadsheet with the replacement purchase date, the original basis, the added wash sale amount, and the adjusted basis is enough.
What Happens if You Claim a Disallowed Loss
Claiming a loss that should have been disallowed understates your tax. If the IRS catches it, you owe the tax plus interest at 7% per year, compounded daily, on the underpayment.9Internal Revenue Service. Interest Rates Remain the Same for the First Quarter of 2026 An accuracy-related penalty of 20% of the underpayment can apply when the IRS determines the error resulted from negligence or disregard of the rules.10Internal Revenue Service. Accuracy-Related Penalty
Ignorance is a weak defense here. The 1099-B reporting system was built to flag these transactions, and overriding a broker’s wash sale adjustment without a valid reason reads as disregard rather than mistake. The quieter and more common error is the opposite: missing a wash sale the broker couldn’t see, usually because the replacement happened in a retirement account. The loss gets claimed in good faith but should never have been. If audited, the recalculation can cascade through the basis of the replacement shares and into later tax years.