When I am doing a mail merge, the comma in the address shows up before the
city and the zip code doesn't show up at all. What can I do to fix it? I
have tried putting apostrophes before the zero-starting zip codes.

This is the format I get:
first-name last-name
address
, city state

This is what I entered in the mail merge:
first-name last-name
address
city, state zip