Follow these Associated Press guidelines for the U.S. states:
The names of the 50 U.S. states should be spelled out when used in the body of a story, whether standing alone or in conjunction with a city, town, village or military base.
Place one comma between the city and the state name, and another comma after the state name, unless ending a sentence or indicating a dateline: He was traveling from Nashville, Tennessee, to Austin, Texas, en route to his home in Albuquerque, New Mexico.
ZIP CODE ABBREVIATIONS: Use the two-letter Postal Service abbreviations only with full addresses, including ZIP code. These abbreviations are two capitalized letters, with no periods.
New Hampshire (NH)
New Jersey (NJ)
New Mexico (NM)
New York (NY)
North Carolina (NC)
North Dakota (ND)
Rhode Island (RI)
South Carolina (SC)
South Dakota (SD)
West Virginia (WV)
WASHINGTON, D.C.: Use state of Washington or Washington state when necessary to distinguish the state from the District of Columbia (Washington, D.C.).