Commas and States/Zip Codes

If you´re writing a full address in the middle of a sentence, complete with zip code, this is the correct format:

Ex: Our address is 12 Brook Lane, Apt. 3, Kansas City, MO 64011.

If you are not providing the zip code, this is the format:

Ex: Our address is 12 Brook Lane, Apt. 3, Kansas City, Missouri.
(If you want to abbreviate the state, it has to be the old formal abbreviation, which in this case would be "Mo.")