All applicants apply online, using either the Middlesex application through Gateway to Prep Schools (Gateway) or the Standard Application Online (SAO). 1. Complete the Student Application Form and submit to your Middle School Counselor. 2.Applications must have a POSTMARK DATE of December 2, 2013. You should contact the admissions office to inform them of your continued interest in attending middlesex. For most programs, the acceptance letter will be viewable within an hour in the applicant's account. Online Application: Complete the application online via the Middlesex County Magnet Schools website. This website provides detailed information about life at Middlesex, and instructions on the application process. Application, Certification and Acceptance of Tuition Chargeback for A County Resident. Attending an Out of County College. Admission Deadlines.