Job grade requirements are based on level of education and previous experience. In general, in order to be eligible to apply for a higher graded position, you must have worked in the next lower grade for at least one year. For example, in order to be eligible to apply for a GS-14 position, you must have worked in a GS-13 position for at least one year. Alternatively, if you are coming from the private sector, you must be able to demonstrate that you have performed GS-13 equivalent work for at least one year. At certain grade levels, educational achievement can sometimes be substituted for work experience. In addition, a combination of educational achievement and work experience can sometimes qualify you for even higher grades.