US Census Bureau

US Census Bureau ACS API

American Community Survey datasets (1-Year, Supplemental, 5-Year)

Documentation GitHub OpenAPI

Operations 5

GET /{vintage}/acs/acs5 Get ACS 5-Year Detailed Tables #

GET /{vintage}/acs/acs5/subject Get ACS 5-Year Subject Tables #

GET /{vintage}/acs/acs5/profile Get ACS 5-Year Data Profiles #

GET /{vintage}/acs/acs1 Get ACS 1-Year Detailed Tables #

GET /{vintage}/acs/acs1/supplemental Get ACS 1-Year Supplemental Estimates #

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OpenAPI Specification

openapi: 3.2.0
info:
  title: Census Data ACS API
  description: 'The Census Data API provides programmatic access to over 1,700 datasets

    published by the U.S.'
  version: '2026-05-25'
  contact:
    name: Census Bureau Developer Support
    email: cnmp.developers.list@census.gov
    url: https://www.census.gov/data/developers/about.html
  license:
    name: Creative Commons Zero 1.0 (Public Domain)
    url: https://creativecommons.org/publicdomain/zero/1.0/
  termsOfService: https://www.census.gov/data/developers/about/terms-of-service.html
servers:
- url: https://api.census.gov/data
  description: Census Data API production base
security:
- ApiKeyQuery: []
tags:
- name: ACS
  description: American Community Survey datasets (1-Year, Supplemental, 5-Year)
paths:
  /{vintage}/acs/acs5:
    get:
      summary: Get ACS 5-Year Detailed Tables
      description: 'Query American Community Survey 5-Year Estimates detailed tables for a

        given vintage (2009 through the latest release year). Returns variables

        for the specified geographies.'
      operationId: getAcs5
      tags:
      - ACS
      parameters:
      - $ref: '#/components/parameters/VintagePath'
      - $ref: '#/components/parameters/GetParam'
      - $ref: '#/components/parameters/ForParam'
      - $ref: '#/components/parameters/InParam'
      - $ref: '#/components/parameters/UcgidParam'
      - $ref: '#/components/parameters/KeyParam'
      responses:
        '200':
          description: ACS 5-Year detailed tables result set (header row + value rows)
          content:
            application/json:
              schema:
                $ref: '#/components/schemas/DataMatrix'
        '400':
          $ref: '#/components/responses/BadRequest'
        '404':
          $ref: '#/components/responses/NotFound'
  /{vintage}/acs/acs5/subject:
    get:
      summary: Get ACS 5-Year Subject Tables
      description: Query ACS 5-Year Estimates Subject Tables (S-prefixed table IDs).
      operationId: getAcs5Subject
      tags:
      - ACS
      parameters:
      - $ref: '#/components/parameters/VintagePath'
      - $ref: '#/components/parameters/GetParam'
      - $ref: '#/components/parameters/ForParam'
      - $ref: '#/components/parameters/InParam'
      - $ref: '#/components/parameters/KeyParam'
      responses:
        '200':
          description: ACS subject tables result set
          content:
            application/json:
              schema:
                $ref: '#/components/schemas/DataMatrix'
  /{vintage}/acs/acs5/profile:
    get:
      summary: Get ACS 5-Year Data Profiles
      description: Query ACS 5-Year Estimates Data Profiles (DP-prefixed table IDs).
      operationId: getAcs5Profile
      tags:
      - ACS
      parameters:
      - $ref: '#/components/parameters/VintagePath'
      - $ref: '#/components/parameters/GetParam'
      - $ref: '#/components/parameters/ForParam'
      - $ref: '#/components/parameters/InParam'
      - $ref: '#/components/parameters/KeyParam'
      responses:
        '200':
          description: ACS data profiles result set
          content:
            application/json:
              schema:
                $ref: '#/components/schemas/DataMatrix'
  /{vintage}/acs/acs1:
    get:
      summary: Get ACS 1-Year Detailed Tables
      description: Query ACS 1-Year Estimates for geographies with 65,000+ population.
      operationId: getAcs1
      tags:
      - ACS
      parameters:
      - $ref: '#/components/parameters/VintagePath'
      - $ref: '#/components/parameters/GetParam'
      - $ref: '#/components/parameters/ForParam'
      - $ref: '#/components/parameters/InParam'
      - $ref: '#/components/parameters/KeyParam'
      responses:
        '200':
          description: ACS 1-Year detailed tables result set
          content:
            application/json:
              schema:
                $ref: '#/components/schemas/DataMatrix'
  /{vintage}/acs/acs1/supplemental:
    get:
      summary: Get ACS 1-Year Supplemental Estimates
      description: Query ACS 1-Year Supplemental Estimates for geographies with 20,000+ population.
      operationId: getAcs1Supplemental
      tags:
      - ACS
      parameters:
      - $ref: '#/components/parameters/VintagePath'
      - $ref: '#/components/parameters/GetParam'
      - $ref: '#/components/parameters/ForParam'
      - $ref: '#/components/parameters/InParam'
      - $ref: '#/components/parameters/KeyParam'
      responses:
        '200':
          description: ACS Supplemental result set
          content:
            application/json:
              schema:
                $ref: '#/components/schemas/DataMatrix'
components:
  responses:
    BadRequest:
      description: Malformed query — for example a missing required parameter, unknown variable, or invalid geography clause.
      content:
        text/html:
          schema:
            type: string
    NotFound:
      description: Dataset, vintage, or variable not found.
      content:
        text/html:
          schema:
            type: string
  schemas:
    DataMatrix:
      type: array
      description: '2-D JSON array. The first inner array is the header row of variable

        names; each subsequent inner array is a record whose elements align

        positionally with the header.

        '
      items:
        type: array
        items:
          type: string
      example:
      - - NAME
        - B01001_001E
        - state
      - - California
        - '39538223'
        - '06'
      - - Texas
        - '29145505'
        - '48'
  parameters:
    ForParam:
      name: for
      in: query
      required: false
      description: Geography clause indicating the geographic level being queried (for example `state:*` or `county:001`).
      schema:
        type: string
        examples:
        - state:*
    GetParam:
      name: get
      in: query
      required: true
      description: Comma-separated list of variables to retrieve. Use the group prefix `group(B19013)` to fetch every variable in a table.
      schema:
        type: string
        examples:
        - NAME,B01001_001E
    InParam:
      name: in
      in: query
      required: false
      description: Hierarchical filter for nested geographies (for example `state:06`).
      schema:
        type: string
        examples:
        - state:06
    VintagePath:
      name: vintage
      in: path
      required: true
      description: Year (or year+month combination) identifying the dataset vintage. Example values include `2024`, `2023`, `2020`.
      schema:
        type: string
        pattern: ^[0-9]{4}([0-9]{2})?$
        examples:
        - '2024'
    KeyParam:
      name: key
      in: query
      required: true
      description: Free API key obtained at https://api.census.gov/data/key_signup.html
      schema:
        type: string
    UcgidParam:
      name: ucgid
      in: query
      required: false
      description: Universal Census Geographic Identifier — alternate single-parameter geography selector.
      schema:
        type: string
        examples:
        - 0400000US06
  securitySchemes:
    ApiKeyQuery:
      type: apiKey
      in: query
      name: key
      description: Free API key obtained at https://api.census.gov/data/key_signup.html

US Census Bureau ACS API

Operations 5

Documentation

Specifications

Schemas & Data

Other Resources