The state abbreviations reference lists all 50 US states with their USPS abbreviations, capital cities, largest cities, and admission dates. Also includes territories and Washington D.C.
US Territories & Washington D.C.
Using US State Abbreviations
USPS two-letter state abbreviations have been standard since 1963. Before that, states used longer abbreviations (Calif., Mass., N.Y.) that varied by style guide. The two-letter codes are now universally used for mail addressing, data entry, legal documents, and all federal systems.
Common confusing abbreviations
Several states have non-obvious abbreviations: Arkansas is AR (not AK which is Alaska), Indiana is IN (not ID which is Idaho), and Mississippi is MS. Montana (MT) is sometimes confused with Minnesota (MN). Maine is ME — not MA, which is Massachusetts.
Frequently Asked Questions
What is the abbreviation for California?
CA. Other commonly confused abbreviations: Colorado is CO, Connecticut is CT, and Canada's province of California-like names use different codes.
Which states have similar abbreviations?
Arkansas (AR) vs Alaska (AK), Indiana (IN) vs Idaho (ID), Minnesota (MN) vs Montana (MT), Maine (ME) vs Massachusetts (MA), and Missouri (MO) vs Mississippi (MS).
Are these USPS abbreviations or old style?
These are the official USPS two-letter abbreviations standardized in 1963. The old style abbreviations (Calif., Mass., N.Y.) are now obsolete for most purposes.
What is DC's abbreviation?
DC stands for District of Columbia. Washington D.C. uses the code DC for mail and is listed as a federal district, not a state or territory.
Is this reference free?
Yes, completely free and no signup required.