Students interested in a joint PhD/MPP at Stanford first apply to the Sociology PhD program, indicating an interest in the joint MPP degree program as part of the Statement of Purpose.
There is one admissions application and one fee. If decision is made by the Sociology Department to admit you, your file is forwarded to the MPP program.
You may also apply after you are enrolled in the Sociology PhD program, by applying first to the Director of Graduate Studies. In all cases, the minimum admissions requirements include consent of the Sociology Department and adequate preparation in economics and mathematics.