A benefit plan, such as a 401(k) or 403(b) plan, that has special tax-qualified benefits and ERISA protections. (By contrast, nonqualified plans do not fit under a section of the Internal Revenue Code.) The requirements for qualified plans are defined in the tax code and regulations. For the special tax deferral and other special tax advantages and legal protections to apply, these rules must be followed. The IRS publishes yearly limits on the maximum contribution amounts and maximum wages that can be considered for these plans. Nonqualified deferred compensation is not a qualified plan.