A defined contribution plan is a type of retirement account in which you contribute money on a regular basis and your employer contributes matching funds. The most common types of defined contribution plan are 401(k)s and 403(b)s, but there are other types as well. The amount that you will receive when you retire depends on how much money you contribute to your account and how well it performs over time. This is in contrast to a defined benefit plan, which pays out a predetermined amount each month once you retire.