Before you complete this form, please read the accompanying literature in the 457. In this comprehensive guide, we will delve into the intricacies of reporting key employee compensation on Form 990.Internal Revenue Code Section 457 provides taxadvantaged treatment for certain nonqualified deferredcompensation plans. Generally, taxexempt organizations are required to limit their activities that are exclusively in furtherance in of their stated mission. A deferred compensation agreement is an agreement between a company and an employee that withholds paying some of the employee's salary.