OP:
Doing a trade is unlikely to work given that if you cancel your slot, it goes back into the pool of available slots. There's no way to do this over the phone or reserve a slot for someone else.
From the USMLE website (the bolding is mine):
It has come to our attention that some Step 2 CS registrants have offered to exchange their scheduled testing appointments for those of other registrants who must take Step 2 CS by specific deadlines. The exchange of testing appointments between applicants is not consistent with the "first-come, first-served" basis on which Step 2 CS testing appointments are offered. It is also highly unlikely to be successful. If you are registered for Step 2 CS, you should know that:
* The Step 2 CS Calendar and Scheduling system does not allow an applicant to reserve his/her scheduled testing appointment for another applicant, nor does it allow the transfer of a testing appointment from one applicant to another. When an applicant cancels a scheduled appointment, the appointment returns to the pool of available testing appointments where it can be claimed by other registrants.
* At any given time, there are many applicants registered for Step 2 CS who may be attempting to schedule or reschedule testing appointments. It is common for appointments that become available to be claimed immediately by another applicant.
* The Step 2 CS Scheduling E-mail Notification System allows registered applicants to indicate their preferences for test dates and centers. When a testing appointment is canceled, all applicants participating in the e-mail notification system who have expressed a preference for this date/center are notified immediately by e-mail.
The best way for registered applicants to monitor the availability of testing appointments is to indicate their preferences for dates/centers using the pilot Step 2 CS Scheduling E-mail Notification System. To indicate your preferences, follow the link Add/Edit Scheduling E-mail Notifications.
For detailed information on policies and procedures related to Step 2 CS scheduling and rescheduling, refer to the USMLE Bulletin of Information.
