Substitute
A substitute is a person who is hired to fill the position of either a professional employe or a temporary professional employe who is absent from the position. The absence of the professional employe may be either for a sabbatical leave or a legal cause that is authorized and approved by the school board. The substitute has no expectation of employment beyond the period of the absence of the person for whom s/he is substituting. A substitute can serve for a very short, per diem, or very long time. Either a professional employe or a certified teacher who is not a professional employe may be employed as a substitute. If a professional employe is hired as a substitute, the emoluments of tenure are not applicable when the returning professional employe or temporary professional employe fills the position. In fact, there is no legal obligation to hire a previously employed substitute for a vacant position as either a professional or a temporary professional employe. A collective bargaining agreement can provide other conditions affecting the current or future employment of substitutes, which can place legal obligations on the school district.
School Code 24 PS §11-1101(2)