What is the difference between a PTA and an OPTA?

A PTA is a Priority TA and an OPTA is an Outside Priority TA. A PTA is when you receive a TA award as part of your funding package at the time of application. If you do not receive this, you may apply as an OPTA when you begin the program. An OPTA is a graduate student who has not been awarded a TA with their offer of admission or a TA that has completed all of their PTA assignments and is continuing in the program on extension. Both a PTA and OPTA must be registered full time in the program.