Vesting is the period over which an employee has the ability to realize rights, usually stock options and/or employer matching contributions to retirement savings plans. For example, a retirement savings plan might have a five-year vesting schedule, where after each year of employment the employee has the right to keep an additional 20 percent of employer contributions to the account. Or, an employee might be vested in 25 percent of his or her stock options after each six months of employment. Vesting schedules vary from company to company. A stock is considered 'vested' when the employee may leave the job, yet maintain ownership of the stock with no consequences. Employees of some companies may need to meet certain requirements after exercising options, such as remaining with the employer for a predefined period, in order to keep the stock.