My educated guess is that it is used without a hyphen when used as a verb, and with a hyphen when used as an adjective.
Dr. Smith is on call. He is the on-call physician.
Similar to follow up:
Dr. Smith will follow up with the patient when she has her follow-up visit.
Yes, "call-out" is hyphenated when used as a noun or an adjective, such as in "a call-out to the community" or "call-out culture." However, when used as a verb, it is written as two separate words, e.g., "to call out someone." Always consider the context to determine the correct usage.
No, "wake up" is not hyphenated. It is typically written as two separate words when used as a verb phrase, such as "I need to wake up early." However, when used as a noun or adjective in a compound form, such as "wake-up call," it is hyphenated.
It is not hyphenated.
Motorcycle is not hyphenated
No it's not hyphenated.
words are only hyphenated when they have a separate meaning when separated than they do when hyphenated
Yes it should be hyphenated.
No, "hardworking" is not hyphenated.
It can be. Some words can be seen both hyphenated and non-hyphenated.
No. Well above is not hyphenated.
peace of mind is not hyphenated.
No, "homework" shouldn't be hyphenated.