Read about US state abbreviations. See the 50 states abbreviations and the state abbreviations list. View a US map with abbreviations and read related history.
Updated: 11/21/2023
U.S. State Abbreviations | Overview, List & Map
Table of Contents
- State Abbreviations: Overview
- Current State Abbreviations List
- US Map with Abbreviations
- Other Ways of Identifying States
- Lesson Summary
Frequently Asked Questions
What US state abbreviation is MD?
MD is the state abbreviation for Maryland. It is used as both the postal abbreviation and the standard abbreviation, and has been in use since the first list of abbreviations was published in 1831.
When did state abbreviations change to two letters?
The first list of state abbreviations, published in 1831, already included primarily two-letter abbreviations. However, there were a number of subsequent changes. The current and now-standard list of two-letter abbreviations was created in 1963.
Table of Contents
- State Abbreviations: Overview
- Current State Abbreviations List
- US Map with Abbreviations
- Other Ways of Identifying States
- Lesson Summary
US state abbreviations are two-letter state initials that are used to distinguish between different states. They are particularly useful when it comes to the postal service, as they provide a quick and space-efficient way of informing mail carriers where to send letters and packages. They are also helpful for shipping and transportation, facilitating commerce and communication across the country and even internationally. However, the current United States abbreviations have not always existed.
History of State Abbreviations
The history of US state abbreviations goes back to 1831 when the first list of abbreviations was published. At that time, only 28 states and regions were included in the list, as fewer states had joined the union. States had two-letter abbreviations in the 1831 list, and territories had two-letter or three-letter abbreviations followed by ''T.'' As a result, Mississippi was abbreviated as ''Mi.'' and Michigan was abbreviated as ''Mic. T.'' States with two-word names, like New York, were abbreviated as two different words, as in ''N. Y.'' which created a further degree of inconsistency in the system. Nonetheless, the system was a step forward and the list underwent several changes over the years.
In 1963, two major changes were implemented in the US postal service. The first was the introduction of zip codes, five-digit numerical codes that designated different regions in the United States in much the same way that postal codes do in other countries. ''Zip'' is actually an acronym that stands for ''Zoning Improvement Program.'' The system was implemented to make shipping easier and faster, with less chance of error.
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In a similar vein, the other change implemented in 1963 was the introduction of a standardized two-letter abbreviation system for all US states plus Washington, DC. This standardized list has undergone virtually no changes since it was first introduced. Today, it is expected that mail sent in the US will include both a postal code and a state abbreviation.
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The current list of abbreviations has undergone just one change since 1963, and that is the alteration of Nebraska's abbreviation from ''NB'' to ''NE.'' This occurred in 1969 at the request of the Canadian postal administration to avoid confusion with New Brunswick, a Canadian province that was also commonly abbreviated to ''NB.''
In 1963, in addition to the standard two-letter abbreviations, the USPS also released longer state abbreviations that were mostly three or four letters long. These longer abbreviations are usually called ''standard'' or ''traditional'' abbreviations, in contrast to postal abbreviations.
| State Name | Standard Abbreviation | USPS Abbreviation |
|---|---|---|
| Alabama | ALA | AL |
| Alaska | ALASKA | AK |
| Arizona | ARIZ | AZ |
| Arkansas | ARK | AR |
| California | CALIF | CA |
| Colorado | COL | CO |
| Connecticut | CONN | CT |
| Delaware | DEL | DE |
| District of Columbia | DC | DC |
| Florida | FLA | FL |
| Georgia | GA | GA |
| Hawaii | HAWAII | HI |
| Idaho | IDAHO | ID |
| Illinois | ILL | IL |
| Indiana | IND | IN |
| Iowa | IOWA | IA |
| Kansas | KANS | KS |
| Kentucky | KY | KY |
| Louisiana | LA | LA |
| Maine | MAINE | ME |
| Maryland | MD | MD |
| Massachusetts | MASS | MA |
| Michigan | MICH | MI |
| Minnesota | MINN | MN |
| Mississippi | MISS | MS |
| Missouri | MO | MO |
| Montana | MONT | MT |
| Nebraska | NEB | NE |
| Nevada | NEV | NV |
| New Hampshire | NH | NH |
| New Jersey | NJ | NJ |
| New Mexico | N MEX | NM |
| New York | NY | NY |
| North Carolina | NC | NC |
| North Dakota | N DAK | ND |
| Ohio | OHIO | OH |
| Oklahoma | OKLA | OK |
| Oregon | ORE | OR |
| Pennsylvania | PA | PA |
| Rhode Island | RI | RI |
| South Carolina | SC | SC |
| South Dakota | S DAK | SD |
| Tennessee | TENN | TN |
| Texas | TEX | TX |
| Utah | UTAH | UT |
| Vermont | VT | VT |
| Virginia | VA | VA |
| Washington | WASH | WA |
| West Virginia | W VA | WV |
| Wisconsin | WIS | WI |
| Wyoming | WYO | WY |
There are a few instances of variation in the standard abbreviations because there was a very similar list published in 1943 and sometimes there is a degree of overlap between the two lists. In most versions, there are seven states whose standard abbreviations are the same as the regular state name: Alaska, Hawaii, Idaho, Iowa, Maine, Ohio, and Utah.
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Many people will have seen a US map with abbreviations naming each state. This can be a very useful way of labeling states without having to write their names out in full. However, it can also be a little confusing, especially for people who do not come from America. For instance, there are 8 states that have abbreviations beginning with M, which can be easy to mix up. Learning to differentiate between all 50 states' abbreviations is a useful skill to have.
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The USPS is not the only organization responsible for finding ways to identify states in the US. There are also military state abbreviations, abbreviations used by the International Organization for Standardization, and state identification from the American National Standards Institute (ANSI).
Military State Abbreviations
There are several abbreviations used specifically by different branches of the US Military. Generally speaking, the military still uses the same two-letter abbreviations that the USPS created, but they add other abbreviations to add military specificity. For example, when sending something to a military organization, it is standard to send it not just to a US address but to a military ''state.'' This means that the state abbreviation should be replaced by AA, which stands for Armed Forces Americas.
There are also specific military post offices that have their own abbreviations and can only be accessed via the USPS. These abbreviations are APO, or Army Post Office, used by the Army and Air Force; FPO, or Fleet Post Office, used by the Navy; and DPO, or Diplomatic Post Office, used by US embassies. The US Coast Guard also has an acronym that it uses: CONUS, or Continental United States.
International Organization for Standardization
The International Organization for Standardization (ISO) is a non-governmental organization that publishes international standards for a wide variety of industries and purposes. One of the goals of the ISO is to standardize country names and abbreviations so that communication can be facilitated around the world. Rather than determining standards individually, the ISO liaises with national standards organizations and publishes aggregate documents of those standards. The American branch of the ISO is called the American National Standards Institute (ANSI).
ANSI Standards
Generally speaking, ANSI uses the same abbreviations as the USPS; the two-letter abbreviations have essentially become the national and international standard. However, ANSI also assigns a two-digit numerical Federal Information Processing Standard (FIPS) code to each state. The first few states, according to ANSI, could be written as follows:
| Alabama | 01 | AL |
| Alaska | 02 | AK |
| Arizona | 04 | AZ |
| Arkansas | 05 | AR |
These codes are in approximately ascending numerical order according to the states' alphabetical listing, with some numbers missing to avoid confusion and to allow for future states to be added to the list.
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In 1963, the United States Postal Service created a list of standardized US state abbreviations that could be used in commerce, communication, transportation, and postal services. This list has become highly standardized and is used by virtually all organizations across the US. Examples of state abbreviations include:
- Hawaii, HI
- Georgia, GA
- Michigan, MI
- Mississippi, MS
- Wyoming, WY
This system is very effective, but it can get a little confusing: there are 8 states that have abbreviations that start with M. In the standard (not postal) abbreviations, most states have three- or four-letter abbreviations, although 7 states have standard abbreviations that are the same as the state names.
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Video Transcript
History of State Abbreviations
The United States is made up of 50 states and a national capital as well as a number of possessions and territories around the world. Because their names are often long, they are frequently abbreviated, or shortened, in written documents and on mailing addresses.
In 1831 and 1874, the United States Postal Service (USPS) published a preferred list of state abbreviations. However, before 1963, the Post Office Department favored people writing out the state and territorial names in full to avoid confusion. For example, Mississippi and Michigan might both be abbreviated MI for their first two letters.
In 1963, the post office put into effect the five-digit ZIP code which would be written after the state abbreviation. At this time, many state abbreviations were made up of four letters. However, due to limited space availability on mailing labels, it was felt that the four letter abbreviations combined with the five-digit zip code contained too many digits. As such, the state abbreviations were amended in October 1963 to the now familiar two letters.
The changeover to the two-letter state abbreviations was not instantaneous. At first, they were optional and intended for use by large businesses to use in conjunction with the new zip codes. To date, there has only been one change to the abbreviations.
In 1969, the postal abbreviation for Nebraska, NB, was changed to NE at a request from the Canadian Postal Administration, in order to avoid confusion with the province of New Brunswick. The United States territories and oversees military installations were also given their own two-digit abbreviations.
Military ''State'' Abbreviations
Have you ever heard of APO or FPO mailing addresses and wondered what they were? Well, they are how mail is sent to military personnel stationed overseas. APO is an acronym (you know the military loves their acronyms) for Army Post Office and includes the Army and Air Force, while FPO stands for Fleet Post Office and includes the Navy and Marine Corps.
These abbreviations take the place of a city name, and then must be used with a ''state'' abbreviation of ''AA'' (Armed Forces Americas), ''AE'' (Armed Forces Europe), or ''AP'' (Armed Forces Pacific). These addresses also utilize special zip codes.
State Abbreviations
The following is a list of the state abbreviations. We'll list the state name, the standard abbreviation, and then the postal abbreviation for each of the 50 states and the nation's capital.
| State | Standard | Postal |
|---|---|---|
| Alabama | Ala. | AL |
| Alaska | Alaska | AK |
| Arizona | Ariz. | AZ |
| Arkansas | Ark. | AR |
| California | Calif. | CA |
| Colorado | Colo. | CO |
| Connecticut | Conn. | CT |
| Delaware | Del. | DE |
| District of Columbia | D.C. | DC |
| Florida | Fla. | FL |
| Georgia | Ga. | GA |
| Hawaii | Hawaii | HI |
| Idaho | Idaho | ID |
| Illinois | Ill. | IL |
| Indiana | Ind. | IN |
| Iowa | Iowa | IA |
| Kansas | Kans. | KS |
| Kentucky | Ky. | KY |
| Louisiana | La. | LA |
| Maine | Maine | ME |
| Maryland | Md. | MD |
| Massachusetts | Mass. | MA |
| Michigan | Mich. | MI |
| Minnesota | Minn. | MN |
| Mississippi | Miss. | MS |
| Missouri | Mo. | MO |
| Montana | Mont. | MT |
| Nebraska | Nebr. | NE |
| Nevada | Nev. | NV |
| New Hampshire | N.H. | NH |
| New Jersey | N.J. | NJ |
| New Mexico | N. Mex. | NM |
| New York | N.Y. | NY |
| North Carolina | N.C. | NC |
| North Dakota | N. Dak. | ND |
| Ohio | Ohio | OH |
| Oklahoma | Okla. | OK |
| Oregon | Oreg. | OR |
| Pennsylvania | Pa | PA |
| Rhode Island | R.I. | RI |
| South Carolina | S.C. | SC |
| South Dakota | S. Dak. | SD |
| Tennessee | Tenn. | TN |
| Texas | Tex. | TX |
| Utah | Utah | UT |
| Vermont | Vt. | VT |
| Virginia | Va. | VA |
| Washington | Wash. | WA |
| West Virginia | W. Va. | WV |
| Wisconsin | Wis. | WI |
| Wyoming | Wyo. | WY |
Lesson Summary
By making standardized abbreviations, or shortened versions, the USPS makes it easier for everyone to recognize and write the states on mail. States have both standard or common abbreviations as well as Postal Service Abbreviations. This allows for the states names to be cut into shorter forms for correspondences and mailing addresses.
In 1963, the state postal codes were formalized into two character abbreviations. It was put into effect at first for big businesses, but was then gradually adopted by everyone as a standardized format. There are even special ''state'' abbreviations for oversees military installations.
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U.S. State Abbreviations | Overview, List & Map
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