I'm considering replacing the shower fixture with a single handle shower. Do combination bath/shower fixtures come with plugs to stop the bath port (outlet) that is not needed or do I have to look for a shower only fixture? Thank you for your help.

Good question ! Yes, most conventional fixtures come with a plug. You just plug the tub-spout outlet and use upper outlet for shower.

I'm considering replacing the shower fixture with a single handle shower. Do combination bath/shower fixtures come with plugs to stop the bath port (outlet) that is not needed or do I have to look for a shower only fixture? Thank you for your help.
Yes, Tub and shower valves Have a 1/2" threaded opening that can be closed off with a 1/2" brass plug making it a "shower only valve". What brand did you have in mind? Regards, Tom

I buy Moen when it is up to me. This is really interestin for some of you. A Moen shower mixer boxed as a shower only valve may go for around $125. If you buy a tub/shower mixer from them it can be the same mixing valve with a few extra pieces to attach the shower head, For $185. The actually valve was the same in both boxes and like Milo and Tom said you just plug the bottom port if you want shower only, plug the top port for tub only. Moen, Buy it for looks, buy it for life- great warranty from these guys.