Humanities › Languages State Abbreviations Why Are There Two Different Abbreviations for the 50 States? Share Flipboard Email Print Rainer Lesniewsk/Getty Images Languages English Grammar Punctuation & Mechanics Using Words Correctly Writing Tips & Advice Sentence Structures Rhetoric & Style Developing Effective Paragraphs Developing Effective Essays Commonly Confused Words Questions & Answers Exercises & Quizzes Topic Suggestions Glossary of Key Terms Readings & Resources English as a Second Language Spanish French German Italian Japanese Mandarin Russian View More by Richard Nordquist Richard Nordquist is a freelance writer and former professor of English and Rhetoric who wrote college-level Grammar and Composition textbooks. Updated May 07, 2018 Wondering when to use abbreviations versus the full names when writing about states? As a general rule, the names of states should be spelled out when they appear in sentences but abbreviated in other contexts. For example: "Our family had been transferred from Endicott, New York, to Raleigh, North Carolina. That was the word used by the people at IBM, transferred." (David Sedaris, "Naked," 1997)"Both men were raised in the Midwest (Garfield in Ohio, Guiteau in Illinois) by a single, widowed parent." (Sarah Vowell, "Assassination Vacation," 2005) This rule applies also if you are writing something formal and following a style guide, such as the Chicago Manual of Style, MLA Style, American Psychological Association Publication Manual (APA), or Associated Press Style (AP). When to Use State Abbreviations In bibliographies, lists, charts where space is at a premium, reference lists, footnotes and endnotes, and in mailing addresses, state names are usually shortened using the postal abbreviation. This applies to Chicago Manual of Style and the American psychological Association Style (APA). The two-letter, no-period state abbreviations recommended by the U.S. Postal Service (See "Postal Abbreviations" in the chart below.) should always be used where a Zone Improvement Plan (ZIP) code follows. These postal abbreviations may also be used in any context where abbreviations are appropriate. Some writers and editors still prefer to use the older forms of state abbreviations. (See "Traditional Abbreviations in the table below.) If you follow this practice, be consistent in your use of the traditional abbreviations, and remember that eight states (Alaska, Hawaii, Idaho, Iowa, Maine, Ohio, Texas, and Utah) are only rarely abbreviated when using the older (pre-ZIP code) forms. Why the ZIP Code Abbreviations Were Developed Before 1963, there were no ZIP codes used on postal mail in the United States, and the U.S. Post Office preferred that people wrote out state and territory names completely to avoid confusion in sorting mail. In the early 1800s, it had established a standardized list of acceptable abbreviations, updating it in 1874. The list remained relatively unchanged until ZIP codes were introduced. The addition of seven additional characters on a final address line (ZIP code plus two spaces) necessitated the shortening of state abbreviations to fewer characters. The Post Office aimed to fit the final address line into 23 characters to accommodate "major addressing systems." U.S. or US for United States Finally, United States may be abbreviated to U.S. when used as an adjective, but in formal writing, it's customarily spelled out as a noun. If you are following the Chicago Manual, you'll remove the periods to become US except in bibliography or reference entries pertaining to U.S. statutes, court cases, and other legal-context usages, which retain the periods. If you're following APA or AP, you will keep the periods there too. MLA prefers to spell out United States as an adjective or a noun in running text. List of State Abbreviations This handy chart has both the postal and the traditional abbreviations, for your reference: STATE POSTAL ABBREVIATION TRADITIONAL ABBREVIATION Alabama AL Ala. Alaska AK Alaska Arizona AZ Ariz. Arkansas AR Ark. California CA Calif. Colorado CO Colo. Connecticut CT Conn. Delaware DE Del. District of Columbia DC D.C. Florida FL Fla. Georgia GA Ga. Hawaii HI Hawaii Idaho ID Idaho Illinois IL Ill. Indiana IN Ind. Iowa IA Iowa Kansas KS Kans. Kentucky KY Ky. Louisiana LA La. Maine ME Maine Maryland MD Md. Massachusetts MA Mass. Michigan MI Mich. Minnesota MN Minn. Mississippi MS Miss. Missouri MO Mo. Montana MT Mont. Nebraska NE Neb. or Nebr. Nevada NV Nev. New Hampshire NH N.H. New Jersey NJ N.J. New Mexico NM N.Mex. New York NY N.Y. North Carolina NC N.C. North Dakota ND N.Dak. Ohio OH Ohio Oklahoma OK Okla. Oregon OR Ore. or Oreg. Pennsylvania PA Pa. Rhode Island RI R.I. South Carolina SC S.C. South Dakota SD S.Dak. Tennessee TN Tenn. Texas TX Tex. or Texas Utah UT Utah Vermont VT Vt. Virginia VA Va. Washington WA Wash. West Virginia WV W.Va. Wisconsin WI Wis. or Wisc. Wyoming WY Wyo. Continue Reading How Should I Write the Abbreviation for 'United States'? Abbreviations and Titles All College Students Should Know What Are the Abbreviations for Canada's 13 Provinces and Territories? The "Going Postal" Epidemic: Workplace Violence on the Rise Popular Style Guides for Writers and When to Use Them Periods Are the Full Stops in Punctuation and in Grammar Citations in Research Papers Bibliography, Reference List or Works Cited? How to Use Initials in Academic Writing Learn How to Keep It Short with These 49 Spanish Abbreviations What Is a ZIP Code? What Are Abbreviations and How Should They Be Used in Formal Writing? All You Need to Know About the History of the U.S. Postal Service History of Mail and the Postal System What Are Postal Codes in Canada? 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