A pension plan is a retirement plan that requires an employer to make contributions to a pool of funds set aside for a worker's future benefit. The pool of funds is invested on the employee's behalf, and the earnings on the investments generate income to the worker upon retirement.
In addition to an employer's required contributions, some pension plans have a voluntary investment component. A pension plan may allow a worker to contribute part of his current income from wages into an investment plan to help fund retirement. The employer may also match a portion of the worker’s annual contributions, up to a specific percentage or dollar amount.