Yes, we are always supposed to specify the state. A standard address looks like this.
Name of person or business
Street # Street Name apt or suite# if there is one
City, State, Zip code four digit extension is optional
Written out for a house:
John Smith
1245 Paradise Lane
Boca Raton, FL 33433
A business might look like this:
Samson Law offices
965 Saginaw Rd. #405
Flint, MI 48825
Attn: Julie Hermann
Mail might move out of a state and back into the same state to get delivered, because of various hub systems both air and ground. For instance mail that starts in western Florida might fly through Memphis, Tennessee to get down to Miami, Florida. Memphis is actually a huge hub for Federal Express, but all major mail carriers use the same format for addressing mail. United Stated Postal Service (USPS) Federal Express (FedEx) and United Parcel Service (UPS).