If a noun is listed as separate words, then it stays separate words -- and is not hyphenated -- as a direct (right in front of the noun) adjective.
...He is in real estate.
...He is a real estate broker.
...He is in high school.
...He is a high school senior.
This gets a little crazy since it means that words need to be looked up even more frequently.
...Odds and ends are being taken care of.
...It is an odds and ends job.
Happy punctuating!
Margie