What is the part of speech for "scheduled" in this sentence?
The baby is scheduled for delivery today.
It's the main verb. It's the action in the sentence, even though it's phrased in the passive voice.
The word "is" is the auxiliary (helping) verb used with "scheduled" in this case. So you would say
baby = subject
is scheduled = main verb
for delivery = prepositional phrase
today = adverb