Complete List of US State Codes (ISO 3166-2:US)

This is a complete reference of all US state and territory codes as defined by the ISO 3166-2:US standard. The table below includes all 50 states, the District of Columbia, and US territories. Each entry shows the ISO 3166-2 code, the two-letter region code used in postal addresses, and the state capital.

All 50 US States

ISO Code	Region Code	State	Capital
US-AL	AL	Alabama	Montgomery
US-AK	AK	Alaska	Juneau
US-AZ	AZ	Arizona	Phoenix
US-AR	AR	Arkansas	Little Rock
US-CA	CA	California	Sacramento
US-CO	CO	Colorado	Denver
US-CT	CT	Connecticut	Hartford
US-DE	DE	Delaware	Dover
US-FL	FL	Florida	Tallahassee
US-GA	GA	Georgia	Atlanta
US-HI	HI	Hawaii	Honolulu
US-ID	ID	Idaho	Boise
US-IL	IL	Illinois	Springfield
US-IN	IN	Indiana	Indianapolis
US-IA	IA	Iowa	Des Moines
US-KS	KS	Kansas	Topeka
US-KY	KY	Kentucky	Frankfort
US-LA	LA	Louisiana	Baton Rouge
US-ME	ME	Maine	Augusta
US-MD	MD	Maryland	Annapolis
US-MA	MA	Massachusetts	Boston
US-MI	MI	Michigan	Lansing
US-MN	MN	Minnesota	Saint Paul
US-MS	MS	Mississippi	Jackson
US-MO	MO	Missouri	Jefferson City
US-MT	MT	Montana	Helena
US-NE	NE	Nebraska	Lincoln
US-NV	NV	Nevada	Carson City
US-NH	NH	New Hampshire	Concord
US-NJ	NJ	New Jersey	Trenton
US-NM	NM	New Mexico	Santa Fe
US-NY	NY	New York	Albany
US-NC	NC	North Carolina	Raleigh
US-ND	ND	North Dakota	Bismarck
US-OH	OH	Ohio	Columbus
US-OK	OK	Oklahoma	Oklahoma City
US-OR	OR	Oregon	Salem
US-PA	PA	Pennsylvania	Harrisburg
US-RI	RI	Rhode Island	Providence
US-SC	SC	South Carolina	Columbia
US-SD	SD	South Dakota	Pierre
US-TN	TN	Tennessee	Nashville
US-TX	TX	Texas	Austin
US-UT	UT	Utah	Salt Lake City
US-VT	VT	Vermont	Montpelier
US-VA	VA	Virginia	Richmond
US-WA	WA	Washington	Olympia
US-WV	WV	West Virginia	Charleston
US-WI	WI	Wisconsin	Madison
US-WY	WY	Wyoming	Cheyenne

District of Columbia

ISO Code	Region Code	Name	Type
US-DC	DC	District of Columbia	District

The District of Columbia is the federal district containing the nation’s capital, Washington, D.C. It is classified as a “District” in ISO 3166-2, not a state. For most software purposes (tax calculation, shipping, forms), DC is treated as equivalent to a state.

US Territories

The United States has several outlying territories. These are classified as “Outlying area” in ISO 3166-2:

ISO Code	Region Code	Territory
US-AS	AS	American Samoa
US-GU	GU	Guam
US-MP	MP	Northern Mariana Islands
US-PR	PR	Puerto Rico
US-VI	VI	Virgin Islands, U.S.
US-UM	UM	United States Minor Outlying Islands

Puerto Rico is the most populous territory with over 3 million residents. For applications involving shipping, taxes, or regulatory compliance, it is important to distinguish between the 50 states, DC, and territories, as different rules may apply.

Looking Up State Data Programmatically

Using @koshmoney/countries, you can look up any US state by its code, name, or get the full list:


import { subdivision } from '@koshmoney/countries';
 
// Look up by full ISO code
subdivision.whereCode('US-CA');
// { code: 'US-CA', name: 'California', type: 'State',
//   countryCode: 'US', countryName: 'United States', regionCode: 'CA' }
 
// Look up by country + region code
subdivision.where('US', 'CA');
// Same result
 
// Look up by name
subdivision.whereName('US', 'California');
// Same result
 
// Get all US subdivisions (states + DC + territories)
const allUS = subdivision.forCountry('US');
console.log(allUS.length); // 56
 
// Filter to just the 50 states
const states = allUS.filter((s) => s.type === 'State');
console.log(states.length); // 50

Converting Between Formats


import { subdivision } from '@koshmoney/countries';
 
// Full code to region code
subdivision.toRegionCode('US-CA'); // 'CA'
 
// Region code to full code
subdivision.toFullCode('US', 'CA'); // 'US-CA'
 
// Code to name
subdivision.toName('US-CA'); // 'California'
 
// Code to country
subdivision.toCountryCode('US-CA'); // 'US'

Validation

Validate state codes before using them in your application:


import { subdivision } from '@koshmoney/countries';
 
// Validate a full ISO code
subdivision.isValidCode('US-CA');  // true
subdivision.isValidCode('US-XX');  // false
 
// Validate a region code for a country
subdivision.isValidRegion('US', 'CA');  // true
subdivision.isValidRegion('US', 'XX');  // false
 
// Validate by name
subdivision.isValidName('US', 'California');  // true
subdivision.isValidName('US', 'Narnia');      // false

Common Use Cases

Tax Calculation

US sales tax is determined at the state (and often local) level. Use ISO 3166-2 codes to identify the correct tax jurisdiction:


import { subdivision } from '@koshmoney/countries';
 
function getTaxRate(stateCode: string): number {
  // Validate the state code first
  if (!subdivision.isValidRegion('US', stateCode)) {
    throw new Error(`Invalid state code: ${stateCode}`);
  }
 
  // Look up tax rate from your database using the standardized code
  return taxRatesByState[stateCode] ?? 0;
}

Shipping Zone Configuration

E-commerce platforms often group states into shipping zones:


import { subdivision } from '@koshmoney/countries';
 
const shippingZones: Record<string, string[]> = {
  'West Coast': ['CA', 'OR', 'WA'],
  'Mountain': ['CO', 'UT', 'MT', 'WY', 'ID', 'NV', 'AZ', 'NM'],
  'Midwest': ['IL', 'IN', 'IA', 'KS', 'MI', 'MN', 'MO', 'NE', 'ND', 'OH', 'SD', 'WI'],
  'Northeast': ['CT', 'DE', 'ME', 'MD', 'MA', 'NH', 'NJ', 'NY', 'PA', 'RI', 'VT'],
  'Southeast': ['AL', 'AR', 'FL', 'GA', 'KY', 'LA', 'MS', 'NC', 'SC', 'TN', 'VA', 'WV'],
  'Texas': ['TX'],
  'Hawaii/Alaska': ['HI', 'AK'],
};
 
function getShippingZone(stateCode: string): string | null {
  for (const [zone, states] of Object.entries(shippingZones)) {
    if (states.includes(stateCode)) return zone;
  }
  return null;
}

Address Forms

When building address forms, populate the state dropdown dynamically:


import { subdivision } from '@koshmoney/countries';
 
// Get states sorted alphabetically (they already are from the library)
const usStates = subdivision.forCountry('US').filter((s) => s.type === 'State');
 
// For a form select element
const options = usStates.map((s) => ({
  value: s.regionCode, // 'CA', 'NY', etc.
  label: s.name,       // 'California', 'New York', etc.
}));

Validating ZIP Codes by State

Combine state codes with postal code validation for complete address verification:


import { subdivision, postalCode } from '@koshmoney/countries';
 
function validateUSAddress(state: string, zip: string): boolean {
  // Validate state code
  if (!subdivision.isValidRegion('US', state)) {
    return false;
  }
 
  // Validate ZIP code format
  if (!postalCode.isValid('US', zip)) {
    return false;
  }
 
  return true;
}
 
validateUSAddress('CA', '90210');      // true
validateUSAddress('CA', '90210-1234'); // true (ZIP+4)
validateUSAddress('XX', '90210');      // false (invalid state)
validateUSAddress('CA', 'ABCDE');      // false (invalid ZIP)

Understanding the Code Format

The ISO 3166-2:US code format is US-{XX}, where XX is a two-letter alphabetic code. This code is the same as the USPS two-letter state abbreviation in all cases. So CA in ISO 3166-2:US is the same CA used on mailing addresses.

The format breaks down as:

US — the ISO 3166-1 alpha-2 country code
- — a hyphen separator (always present)
XX — the two-letter subdivision code

This makes US subdivision codes particularly developer-friendly since they match the widely used USPS abbreviations.

Get Started

Look up any US state code programmatically with @koshmoney/countries:


npm install @koshmoney/countries


import { subdivision } from '@koshmoney/countries';
 
const california = subdivision.where('US', 'CA');
console.log(california.name); // 'California'

See the full Subdivision API documentation for all available functions.