These are retirement plans that do not meet the requirements under the Internal Revenue Code. These types of plans are usually used to reward highly-compensated employees and key executives without having to meet nondiscrimination rules.
In order for an employee to receive tax-deferred treatment, a nonqualified plan must be unfunded, or the employee must be at risk to lose the benefits. The employer cannot deduct the contributions to a nonqualified plan until the amounts are included in the employee's compensation.