I know that according to the NEC, a bathroom circuit must be 20amp GFCI protected and can not power any outlets/lights outside of the bathroom. My question is, can two adjacent bathrooms (a full bath and half bath if it matters) share a single circuit under the code? If it is legal are the any practical reasons not to do this? I am remodeling an old house and for a variety of reasons sharing one circuit would be much easier.

Thank you.

The circuit you are referring to only applies to the receptacles.

The code is that IF the circuit is contained to just one bathroom, you can have everything in that one bathroom on the required 20A receptacle circuit. This includes lighting, and fans. Not anything that would require it's own circuit like electric heat.

If you run a 20A circuit just for the receptacle(s) in a bath, that same circuit can legally be shared with receptacles (only) in any/all baths in the house.

Ahh, thanks for the answer. I will wire each bathroom with a separate circuit. In my situation the sharing will not reduce the challenges of the remodel.