I'll try to do this question justice. When you have the pleasure of applying to medical school, you will inevitably have to deal with this organization called AMCAS (American Medical College Application Service). Essentially, this organization collects all of your primary data (grades, activities, personal statement, etc) and transmits them to the medical schools you designate in your application. Now mind you, transmission of your application may or may not happen. It all depends on whether or not the AMCAS gods are with you. Before transmitting, they must verify your grades, and input your MCAT scores. According to page 12 of the AMCAS user agreement, no applications will be processed after October 1st unless they are accompanied by a letter from your lawyer threatening legal action. For this great service that AMCAS provides you, they charge you a small fee. $150 for the first school, and $30 for each additional school. Many on this board have complained vociferously regarding these fees, contending that they are exorbitant. I, on the other hand, feel that they are necessary and equitable. After all, when you apply to medical school, you will undoubtedly have to call AMCAS. The people at AMCAS whose sole job it is to take your call are "specialists." These are highly trained individuals who have many years of experience with regards to the medical school application cycle. Needless to say, employees such as these do not come cheaply, hence the justification of the aforementioned fees. Anyways, after AMCAS has transmitted your primary application to your designated medical schools, many schools will send you a secondary application. These application vary in length and content. They go from the "Click here to send us $100" from New York Medical College, to much lengthier versions with numerous essays asking you to "analyze why queue is the only word in the English language with 5 consecutive vowels." Did anyone else find that essay ridiculous? Anyway, secondary applications almost always require you to submit a processing fee. Many others also request photos. Anyway, sorry for the longwinded response, I simply wanted to do this question justice.