American Community Survey (ACS) API - Complete Variable Reference

American Community Survey (ACS) API - Complete Variable Reference

API Overview

Endpoint: https://api.census.gov/data/{year}/acs/{survey}

Description: Provides detailed demographic, social, economic, and housing statistics for the U.S. population. Updated annually with 1-year and 5-year estimates.

Survey Types:

  • acs1 - 1-year estimates (areas with 65,000+ population)
  • acs5 - 5-year estimates (all geographic areas, including small areas)

Update Frequency: Annual

Use Cases for Business Initiative:

  • Market demographics and population analysis
  • Income and economic characteristics
  • Education levels
  • Housing and cost of living
  • Employment and occupation data
  • Geographic market analysis

Variable Naming Convention

ACS variables follow a structured naming pattern:

Format: B{TableNumber}_{SequenceNumber}{EstimateType}

  • B: Base table prefix
  • Table Number: 5-digit number (e.g., 01003)
  • Sequence Number: 3-digit number (e.g., 001)
  • Estimate Type:
    • E - Estimate
    • M - Margin of error
    • C - Count (for some tables)

Example: B01003_001E

  • B01003 = Table B01003 (Total Population)
  • 001 = First sequence (Total)
  • E = Estimate

Core Demographic Variables

Population Variables

B01003_001E - Total Population

  • Description: Total population count
  • Table: B01003 (Total Population)
  • Use Case: Market size, population trends
  • Example: 38,965,193 (California 2023)

B01001_001E - Total Population (by Sex)

  • Description: Total population by sex
  • Table: B01001 (Sex by Age)
  • Related: B01001_002E (Male), B01001_026E (Female)

B01002_001E - Median Age

  • Description: Median age of population
  • Table: B01002 (Median Age by Sex)
  • Use Case: Age demographics for market targeting

Age Variables

B01001_002E through B01001_025E - Male Age Groups

  • Description: Male population by age groups
  • Age Ranges: Under 5, 5-9, 10-14, …, 75-79, 80-84, 85+

B01001_026E through B01001_049E - Female Age Groups

  • Description: Female population by age groups
  • Use Case: Age-specific market analysis

Race and Ethnicity Variables

B02001_001E - Total Population (Race)

  • Description: Total population for race tabulation
  • Table: B02001 (Race)

B02001_002E - White Alone

  • Description: Population identifying as White alone

B02001_003E - Black or African American Alone

  • Description: Population identifying as Black or African American alone

B02001_004E - American Indian and Alaska Native Alone

  • Description: Population identifying as American Indian/Alaska Native alone

B02001_005E - Asian Alone

  • Description: Population identifying as Asian alone

B03003_001E - Total Population (Hispanic/Latino)

  • Description: Total population for Hispanic/Latino tabulation
  • Table: B03003 (Hispanic or Latino Origin)

B03003_002E - Not Hispanic or Latino

B03003_003E - Hispanic or Latino

Economic Variables

Income Variables

B19013_001E - Median Household Income

  • Description: Median income in the past 12 months (inflation-adjusted dollars)
  • Table: B19013 (Median Household Income)
  • Use Case: Market purchasing power, pricing strategies
  • Example: $91,551 (median household income)

B19025_001E - Aggregate Household Income

  • Description: Sum of all household incomes
  • Table: B19025 (Aggregate Household Income)
  • Use Case: Total market spending power

B19301_001E - Per Capita Income

  • Description: Per capita income in past 12 months
  • Table: B19301 (Per Capita Income)
  • Use Case: Individual purchasing power

Income by Source

  • B19052_001E - Aggregate Wages and Salaries
  • B19053_001E - Aggregate Self-Employment Income
  • B19054_001E - Aggregate Interest, Dividends, or Net Rental Income

Employment Variables

B23025_001E - Population 16 Years and Over

  • Description: Total population in labor force age
  • Table: B23025 (Employment Status)

B23025_002E - In Labor Force

  • Description: Population in labor force

B23025_003E - Civilian Labor Force

B23025_004E - Employed

B23025_005E - Unemployed

B23025_006E - Not in Labor Force

B23025_007E - Unemployment Rate

  • Description: Unemployment rate (calculated)
  • Use Case: Labor market conditions

Occupation Variables

B24010_001E - Total Population 16 Years and Over (Occupation)

  • Description: Total for occupation tabulation
  • Table: B24010 (Sex by Occupation)

Common Occupation Categories:

  • Management, Business, Science, and Arts Occupations
  • Service Occupations
  • Sales and Office Occupations
  • Natural Resources, Construction, and Maintenance Occupations
  • Production, Transportation, and Material Moving Occupations

Industry Variables

B24030_001E - Total Population 16 Years and Over (Industry)

  • Description: Total for industry tabulation
  • Table: B24030 (Sex by Industry)

Common Industry Categories:

  • Agriculture, Forestry, Fishing and Hunting, and Mining
  • Construction
  • Manufacturing
  • Wholesale Trade
  • Retail Trade
  • Transportation and Warehousing, and Utilities
  • Information
  • Finance and Insurance, and Real Estate and Rental and Leasing
  • Professional, Scientific, and Management, and Administrative and Waste Management Services
  • Educational Services, and Health Care and Social Assistance
  • Arts, Entertainment, and Recreation, and Accommodation and Food Services
  • Other Services (except Public Administration)
  • Public Administration

Education Variables

B15003_001E - Total Population 25 Years and Over (Education)

  • Description: Total for education attainment
  • Table: B15003 (Educational Attainment)

Education Levels:

  • Less than 9th grade
  • 9th to 12th grade, no diploma
  • High school graduate
  • Some college, no degree
  • Associate’s degree
  • Bachelor’s degree
  • Master’s degree
  • Professional degree
  • Doctorate degree

Use Case: Market education levels, target audience analysis

Housing Variables

B25077_001E - Median Home Value

  • Description: Median value of owner-occupied housing units
  • Table: B25077 (Median Value)
  • Use Case: Cost of living, market analysis

B25064_001E - Median Gross Rent

  • Description: Median gross rent
  • Table: B25064 (Median Gross Rent)
  • Use Case: Cost of living, rental market

B25001_001E - Total Housing Units

  • Description: Total housing units
  • Table: B25001 (Housing Units)

Business/Entrepreneurship Relevant Variables

Self-Employment

B24050_001E - Total Population 16 Years and Over (Class of Worker)

  • Description: Total for class of worker
  • Table: B24050 (Sex by Class of Worker)

Class of Worker Categories:

  • Private wage and salary workers
  • Government workers
  • Self-employed in own incorporated business
  • Self-employed in own not incorporated business
  • Unpaid family workers

Use Case: Self-employment rates, entrepreneurship analysis

Commuting/Work Location

B08301_001E - Total Workers 16 Years and Over (Means of Transportation)

  • Description: Total for transportation to work
  • Table: B08301 (Means of Transportation to Work)

Transportation Modes:

  • Car, truck, or van
  • Public transportation
  • Walked
  • Bicycle
  • Worked from home

Use Case: Remote work trends, location preferences

Geography Options

National Level

  • us:* - United States total

State Level

  • state:* - All states
  • state:06 - California (2-digit FIPS code)
  • Multiple: state:06,36,48

County Level

  • county:* - All counties (within state)
  • state:06&county:* - All counties in California
  • state:06&county:037 - Los Angeles County, CA

Metropolitan Areas

  • metropolitan statistical area/micropolitan statistical area:* - All MSAs
  • metropolitan statistical area/micropolitan statistical area:31080 - Los Angeles-Long Beach-Anaheim MSA

Place Level

  • place:* - All places (cities, towns)
  • state:06&place:* - All places in California

Census Tract

  • tract:* - All census tracts (within county)
  • state:06&county:037&tract:* - All tracts in Los Angeles County

Survey Type Options

acs1 (1-Year Estimates)

  • Coverage: Areas with 65,000+ population
  • Use Case: Large metro areas, states, national data
  • Example: https://api.census.gov/data/2023/acs/acs1

acs5 (5-Year Estimates)

  • Coverage: All geographic areas, including small areas
  • Use Case: Small cities, counties, census tracts
  • Example: https://api.census.gov/data/2023/acs/acs5

Year Parameters

  • Required: Yes
  • Format: 4-digit year
  • Range: 2005 to present (varies by survey type)
  • Note: acs5 data represents 5-year period (e.g., 2019-2023)

Margin of Error Variables

All estimate variables have corresponding margin of error variables:

  • Estimate: B01003_001E (Total Population)
  • Margin of Error: B01003_001M (Margin of error for total population)

Use Case: Statistical reliability, confidence intervals

Example API Calls

Example 1: Total Population by State (2023)

GET https://api.census.gov/data/2023/acs/acs1
Parameters:
  get: NAME,B01003_001E
  for: state:*
  key: YOUR_API_KEY

Example 2: Median Income and Education (California, 2023)

GET https://api.census.gov/data/2023/acs/acs1
Parameters:
  get: NAME,B19013_001E,B15003_022E,B15003_023E
  for: state:06
  key: YOUR_API_KEY
  • B19013_001E: Median household income
  • B15003_022E: Bachelor’s degree
  • B15003_023E: Master’s degree

Example 3: Self-Employment by State (5-Year Estimates)

GET https://api.census.gov/data/2023/acs/acs5
Parameters:
  get: NAME,B24050_004E,B24050_005E
  for: state:*
  key: YOUR_API_KEY
  • B24050_004E: Self-employed in incorporated business
  • B24050_005E: Self-employed in not incorporated business

Example 4: Employment by Industry (Metro Area)

GET https://api.census.gov/data/2023/acs/acs1
Parameters:
  get: NAME,B24030_001E,B24030_002E
  for: metropolitan statistical area/micropolitan statistical area:31080
  key: YOUR_API_KEY

Common Variable Combinations for Business Initiative

Market Demographics

Variables: B01003_001E, B19013_001E, B15003_022E
Geography: state:* or county:*
Use: Market size, income, education levels

Entrepreneurship Analysis

Variables: B24050_004E, B24050_005E (self-employment)
Geography: state:* or metropolitan statistical area/micropolitan statistical area:*
Use: Self-employment rates, entrepreneurship trends

Labor Market Analysis

Variables: B23025_004E, B23025_005E, B23025_007E
Geography: state:* or county:*
Use: Employment rates, unemployment, labor market health

Industry Analysis

Variables: B24030_* (industry variables)
Geography: state:* or metropolitan statistical area/micropolitan statistical area:*
Use: Industry employment distribution

Finding Variables

Method 1: Census Data API Discovery Tool

  • URL: https://api.census.gov/data.html
  • Search by topic (e.g., “income”, “employment”, “education”)
  • Browse available tables

Method 2: ACS Data Tables

  • URL: https://data.census.gov/cedsci/
  • Browse tables by topic
  • Variable codes are listed in table documentation

Method 3: Variable Naming Patterns

  • B01xxx: Population and age
  • B02xxx: Race
  • B03xxx: Hispanic/Latino origin
  • B15xxx: Education
  • B19xxx: Income
  • B23xxx: Employment status
  • B24xxx: Occupation and industry
  • B25xxx: Housing

Data Limitations & Notes

  1. Sample Size: acs1 requires 65,000+ population for reliability
  2. Time Period: acs5 represents 5-year averages
  3. Suppression: Small areas may have suppressed data
  4. Margin of Error: Always consider MOE for statistical reliability
  5. Year Availability: Latest year typically 1-2 years behind current year

MCP Tool Usage

Tool Name: fetch_census_acs_data

Example Call:

{
  "year": 2023,
  "variables": ["B01003_001E", "B19013_001E", "B15003_022E"],
  "geography": "state:06",
  "survey": "acs1"
}

References

  • Official Documentation: https://www.census.gov/data/developers/data-sets/acs-5year.html
  • Variable List: https://api.census.gov/data/2023/acs/acs1/variables.html
  • Table List: https://data.census.gov/cedsci/
  • API User Guide: https://www.census.gov/data/developers/guidance/api-user-guide.html