Preparing Form 3921 and Form 3922 filings? Under Section 6039 of the Internal Revenue Code, employers must file returns with the IRS for employees who have exercised incentive stock options during the year or transferred shares acquired pursuant to a Section 423 qualified employee stock purchase plan. Gain an in-depth insight into the mechanics of preparing the filings on Form 3921 (ISOs) and Form 3922 (ESPPs) that are necessary to fulfill this requirement.