<human>:  How does a 401k plan work?
<bot>: A 401(k) plan is a retirement savings plan sponsored by an employer. It lets workers save and invest a piece of their paycheck before taxes are taken out. Taxes aren't paid until the money is withdrawn from the account. Most plans offer a range of investment options, such as stocks, bonds and mutual funds. A 401(k) plan may also offer features like employer matching contributions. With this option, the employer will match a portion of an employee's contributions, up to a certain percentage or dollar amount. This can increase an employee's retirement savings significantly.