You can either power everything in one bathroom from one 20 amp circuit or you can power just the receptacles in as many bathrooms as you want with one 20 amp circuit.
Check out 210.11(C)(2)
Bob Badger Construction & Maintenance Electrician Massachusetts
I understand, i was just taught that each bathroom GFCI outlet has it's own circuit. This did not have anything else on it. So I would need 3 HR's for the bathrooms. Not including lights. Just outlet.
One dedicated 20 amp branch circuit to each bathroom is the better install, in my opinion. But it's only an opinion and a design issue. The Code allows for the (1) 20 amp circuit to be "jumped-out" to all the other bathroom as long as nothing else is on the circuit besides bathroom recpeptacles. The Code also allows for lighting to be included on this 20 amp circuit as long this circuit doesn't feed other bathrooms.
If you want to be nice, 2 circuits. 1 in the master and the other feeding the other 2. one of those other 2 is most likely gonna be a 1/2 bath where the plug ussually is not used much.