Students without any connection with the Graduate Programs at USP or students regularly enrolled in Graduate Programs at other universities (for more details, check articles 58 and 59 in the bylaws of the Graduate Program at USP).
Fee: 150 BRL (Brazilian reais) for enrollment, by discipline, for special students. You can pay the fee at the Finance Office (tesouraria) at the Faculty of Medicine at USP, after receiving a payment slip (guia de recolhimento) from the Graduate Program Administration office (serviço de pós-graduação).
You can pay in cash or by check payable to the Faculdade de Medicina da Universidade de São Paulo. There is no specific period for the enrollment as a special student. Just be sure to complete it until the start date.
For enrollment, proceed to the administration office of the Graduate Program (serviço de pós-graduação) at FMUSP from 9 a.m. to 3:30 p.m. Be sure to bring the following documents:
1) legible copy of the RNE
2) legible copy of the CPF
3) legible copy of the diploma from your undergraduate education (front and back)
4) enrollment form filled with the discipline(s) code(s) and the signature(s) from the professor(s) in charge
The requirements for the special students enrollment in the Faculty of Medicine at USP can be confirmed here.