"Employer matching" in a retirement plan means that your employer contributes a certain amount to your retirement plan based on how much you contribute. For example, if your employer offers a 9% match, and you contribute 9% of your salary, they will equal that amount. If you contribute 4%, they will contribute 4%; if you contribute 10%, they will contribute 9%. You usually have to work at the company for a set amount of time to become "vested" and keep the employer contributions if you leave your job.