Not a current student but the parent of one. DD is currently triple majoring. If one of your intended majors has admission controls you need to declare that major first. Adding the second major is a matter of a few signatures: adviser, department head, and dean of each college where your current and intended major resides. It helps if the majors are closely related so you can cross count a lot of courses. You also need to list courses, numbers, and credits to be completed in both programs after the current semester. Include: General Education, College, and Major requirements. See application here:
http://www.psu.edu/oue/aappm/concurrent.pdf 
