IRS Form 3921, Exercise of an Incentive Stock Option under Section 422(b) is a form filed with the Internal Revenue Service (IRS) by corporations that offer their employees an incentive stock option (ISO) described in Section 422(b). IRS Form 3921 is issued by the IRS and was last revised in October 2017. A fillable version of the form can be found below.
Any corporation that grants their employees an ISO uses IRS 3921 Form to report the IRS about their transfers of stock made to any transferee when that transferee exercises an ISO under Section 422(b). ISO is a type of employee compensation in the form of stock, which allows the employee to purchase stock, either in the employer's corporation or a parent or subsidiary, usually exercised at a price below the market price.