09/24/2026
Already taxed through payroll does not mean the stock-sale form can be ignored.
When employer stock is sold, the W-2 and Form 1099-B need to be reviewed together. A basis figure that does not account for compensation already taxed as wages can overstate the capital gain if the required adjustment is missed.
Keep the stock-plan statements and exercise or vesting records alongside the tax forms. Our article explains the reporting issue and why different types of equity compensation need different treatment.
https://zagmoutcpas.com/the-double-tax-trap-hidden-in-your-stock-option-form-1099-b/
Navigating stock option 1099-B cost basis can be tricky. Avoid double taxation by understanding how compensation and gains intersect.