In medical transcription, we do not use follow-up anymore so you can eliminate that one. We have followup and follow up left.
If you can remember that followup is a noun or adjective and follow up is a verb, that is half the battle.
The patient had a followup scheduled for her primary physician.
She has a followup appointment today.
I am going to follow up with the patient.
Angie suggested I tell you the rule she goes by when working with followup and follow up:
If “in” or “a” or “for” is in front of “followup,” then use the one-word followup.
If “to” or “will” is in front of “follow up,” then use the two-word follow up.
Hope that helps!

{ 4 comments… read them below or add one }
Thanks for the follow-up not being used at all anymore. That actually was one of the choices I was still taking into consideration and I’ve been typing a long time!
Follow up (two words) can also be used as a verb.
Lee, thank you for the information. I will add it to the post.
Thanks a lot