53 Pa. Stat. § 23445
The competitive class shall include all positions and employments now existing or hereafter created, of whatever functions, designations, or compensation, in each and every branch of the classified service, except such positions as are in the exempt class, the noncompetitive class, or the labor class. Appointments shall be made to, or employment shall be given in, all positions in the competitive class that are not filled by promotion, reinstatement, transfer, or reduction, under the provisions of this act and the rules made in pursuance thereof, by appointment from among those certified to the appointing officer, in accordance with the provisions of section fourteen of this act. The term of eligibility of an applicant shall be fixed, for each list, by the civil service commission, at not less than one nor more than three years. The names of those persons eligible for appointment shall always be listed and certified in the order of their gradings, beginning with the highest. Appointments shall be made from the eligible list most nearly appropriate, and a new and separate list shall be created only when there is no appropriate list existing from which appointments may be made. No person shall be appointed or employed under any title not appropriate to the duties to be performed; and no person shall be transferred to any position subject to a competitive examination unless he shall have previously passed an open, competitive examination equivalent to that required for such position.
53 P.S. § 23445