Buying back a substantially identical security too soon after a loss sale doesn’t erase the loss — it just defers the tax benefit rather than eliminating it.
How it works
If a repurchase happens within 30 days before or after the sale (a 61-day window total), the loss is disallowed for the current year and instead added to the cost basis of the replacement shares — deferring, not eliminating, the tax benefit.
What this does not include
The wash sale rule applies across all accounts, including a spouse’s accounts and IRAs, per Fidelity’s own summary — this calculator checks the timing rule itself, not whether a specific repurchase in a different account or by a spouse would also trigger it.
How to use this calculator
- Enter the realized loss and the original cost basis of the shares sold.
- Enter the number of days between the sale and any repurchase.
Frequently asked questions
Does the wash sale rule apply if I buy back a different but similar stock?
Only if the repurchased security is “substantially identical” — buying a different company’s stock in the same sector generally doesn’t trigger it, though buying back into the same fund often does.
Is the disallowed loss gone forever?
No — it’s added to the basis of the replacement shares, so it reduces the taxable gain (or increases the loss) whenever those replacement shares are eventually sold.
Does the wash sale rule apply to an IRA?
Yes — selling at a loss in a taxable account and buying the same security in an IRA within the window can trigger a wash sale, and in that case the disallowed loss may be permanently lost rather than added to a basis.
