It is highly likely that your part-time tuition includes your 2nd(?) health insurance (i.e., not free).
With a proof of coverage under your PPO through your employment, you can request to get a waiver for the 2nd health health insurance. In a remote chance that you get the free coverage through your part-time grad program, my best educated guess is that you will be covered by either (not both) of your health insurance.
