When you talk about the investment vehicles like 401(k)/IRA/non-Roth IRA, you may encounter another set of terms: qualified and non-qualified plans.

In short, qualified retirement plans give employers a tax break for any contributions they make for their employees - thus it can be very attractive to many employers. What normally happens is that the employees also get to put pre-tax money into the account (a qualified retirement plan), and the employees don't pay taxes on the investment gains from the account, until they withdraw the money later in life (thus called "pre-tax contribution").

From the employee perspective, qualified retirement plan is equal for every employee: employers must offer qualified plans to every employee as long as those employees meet a very minimal requirement (for instance, one year of full-time employment). All employees cannot be treated differently based on their compensation levels, meaning that the upper-level executives at a higher salary rate cannot receive some "special arrangements/matches" in qualified plans.

The down side for qualified plans is that for they normally have restrictions on when you can withdraw the money. If you withdraw early, you will be penalized. Various plans may come with different terms and requirements, so make sure you scrutinize the terms carefully before you make the move.As for non-qualified plans , they are part of your retirement package, but they usually have their own rules for contributions, and in general offer the employers no tax break. Non-qualified plans often allow employees to defer taxes until retirement, but they aren't deductible to the employers.Therefore, non-qualified plans are often extra "benefits" offered to higher level employees only, provided that there is no rule requiring that everybody must be "treated equally" in the setup of non-qualified plans. This is a huge difference from qualified plans.In terms of the maximum contribution amount, employees and employers can contribute without the upper limit. Especially for high-level employees, non-qualified plans could potentially be a good consideration to save money for retirement.