Anyone taking a higher degree should check with the Degrees Officer for the precise arrangements that apply to their specific circumstances.
The academical dress for higher degrees depends both on the degree to be take and on the relationship with the University
If you already posses a degree from the University of Cambridge, then you wear the academic dress appropriate to that degree. If this is your first degree from Cambridge, then you wear the hood of the degree that you are taking and the gown of your current status.
Other formal dress is as described in 'Dress code for the degree ceremony' page.