Centers for Medicare and Medicaid Services Geography API
Geographic data, including information on states, counties, and zipcodes.
Work with this as data
Every API here is available over the APIs.io API and to AI agents over MCP.
MCP server
One button, every client — Claude, Cursor, VS Code and the rest.
https://apis.io/mcp
Tools for apis
7 MCP tools reach this
find_apisBrowse and filter every API in the catalog.get_api_artifactsOne API's artifacts, grouped by type.get_openapiThe primary OpenAPI for this API.find_similar_apisAPIs that look like this one.apis_io_searchSTART HERE — APIs, providers and tags for one query, each with its total.resolveTurn a domain, URL or GitHub org into the provider it belongs to.find_cohortsEvery scored population of providers in the catalog.
Call it yourself
curl for this page
This API
curl "https://apis.io/api/v1/apis/cms-geography-api"
All apis
curl "https://apis.io/api/v1/apis?limit=25"Discovery needs no key. Ratings and market analysis are Pro.
Get an API key
Free tier, no form to fill in. Signing in shares your email address with us — we store it to create your key and to recognise you if you sign in with another provider. See our Privacy Policy and Terms.
A second provider on the same verified email joins the account you already have.
OpenAPI Specification
openapi: 3.2.0
info:
title: Marketplace Geography API
version: '1'
description: '# About
The Marketplace API delivers data that helps users find and evaluate health care insurance plans, providers, and coverage information on the marketplace.'
servers:
- url: https://marketplace.api.healthcare.gov/api/v1
security:
- API Key: []
tags:
- name: Geography
description: Geographic data, including information on states, counties, and zipcodes.
paths:
/counties/by/zip/{zipcode}:
x-summary: List Counties by ZIP
get:
tags:
- Geography
description: 'Find counties matching ZIP Code (5 digits or prefix thereof).
This method is suitable for use in typeahead UI completions.'
parameters:
- $ref: '#/components/parameters/apikey'
- $ref: '#/components/parameters/year-with-default'
- $ref: '#/components/parameters/zipcode'
responses:
'200':
description: Successful response
content:
application/json:
schema:
properties:
counties:
items:
$ref: '#/components/schemas/ZIPCounty'
example:
- fips: '12345'
name: Sedgwick County
state: KS
zipcode: '67203'
type: array
type: object
summary: Get counties by zip by zipcode
x-summary-source: derived
operationId: getCountiesByZipByZipcode
x-operation-id-source: derived
/counties/{fips}:
x-summary: County Lookup by FIPS
get:
tags:
- Geography
description: Get information about a county by its FIPS code.
parameters:
- $ref: '#/components/parameters/apikey'
- $ref: '#/components/parameters/year-with-default'
- $ref: '#/components/parameters/fips'
responses:
'200':
description: Successful response
content:
application/json:
schema:
$ref: '#/components/schemas/County'
summary: Get counties by fips
x-summary-source: derived
operationId: getCountiesByFips
x-operation-id-source: derived
/states:
x-summary: List States
get:
tags:
- Geography
description: List all U.S. states.
parameters:
- $ref: '#/components/parameters/apikey'
- $ref: '#/components/parameters/year-with-default'
responses:
'200':
description: Successful response
content:
application/json:
schema:
properties:
states:
items:
$ref: '#/components/schemas/State'
type: array
example:
- name: Nevada
abbrev: NV
fips: '32'
marketplace_model: SBM
shop_marketplace_model: SBM
hix_name: Nevada Health Link
hix_url: https://www.nevadahealthlink.com/
shop_hix_name: Nevada Health Link
shop_hix_url: https://www.nevadahealthlink.com/
8962_link: ''
8965_link: ''
assister_program_url: https://www.nevadahealthlink.com/find-assistance/
- name: New York
abbrev: NY
fips: '36'
marketplace_model: SBM
shop_marketplace_model: SBM
hix_name: NY State of Health
hix_url: https://nystateofhealth.ny.gov/
shop_hix_name: NY State of Health
shop_hix_url: https://nystateofhealth.ny.gov/
8962_link: ''
8965_link: ''
assister_program_url: https://nystateofhealth.ny.gov/agent/assistors
type: object
summary: Get states
x-summary-source: derived
operationId: getStates
x-operation-id-source: derived
/states/{abbrev}:
x-summary: Lookup State
get:
tags:
- Geography
description: Get a U.S. state from its 2-letter USPS abbreviation.
parameters:
- $ref: '#/components/parameters/apikey'
- description: 2-letter USPS state abbreviation, uppercased.
in: path
name: abbrev
required: true
x-example: NV
schema:
type: string
- $ref: '#/components/parameters/year-with-default'
responses:
'200':
description: Successful response
content:
application/json:
schema:
$ref: '#/components/schemas/State'
summary: Get states by abbrev
x-summary-source: derived
operationId: getStatesByAbbrev
x-operation-id-source: derived
/states/{abbrev}/medicaid:
x-summary: State Medicaid Data
get:
tags:
- Geography
description: Get Medicaid data for a U.S. state for a specific fiscal year.
parameters:
- $ref: '#/components/parameters/apikey'
- description: 2-letter USPS state abbreviation, uppercased.
in: path
name: abbrev
required: true
x-example: NV
schema:
type: string
- $ref: '#/components/parameters/year-with-default'
- description: 1-4 A specific fiscal quarter. When not specified it defaults to the most current data for the specified year
in: query
name: quarter
required: false
x-example: '2'
schema:
type: string
responses:
'200':
description: Successful response
content:
application/json:
schema:
$ref: '#/components/schemas/StateMedicaid'
summary: Get states by abbrev medicaid
x-summary-source: derived
operationId: getStatesByAbbrevMedicaid
x-operation-id-source: derived
/states/{abbrev}/poverty-guidelines:
x-summary: State Poverty Guidelines
get:
tags:
- Geography
description: Get U.S. federal poverty guidelines for the provided state.
parameters:
- $ref: '#/components/parameters/apikey'
- description: 2-letter USPS state abbreviation, uppercased.
in: path
name: abbrev
required: true
x-example: NV
schema:
type: string
- $ref: '#/components/parameters/year-required'
responses:
'200':
description: Successful response
content:
application/json:
schema:
$ref: '#/components/schemas/PovertyGuideline'
summary: Get states by abbrev poverty guidelines
x-summary-source: derived
operationId: getStatesByAbbrevPovertyGuidelines
x-operation-id-source: derived
/rate-areas:
x-summary: Rate Area Lookup
get:
tags:
- Geography
description: Get market year rate area for a given zip/fips/state.
parameters:
- $ref: '#/components/parameters/apikey'
- description: 2-letter USPS state abbreviation
in: query
name: state
required: true
schema:
type: string
- description: 5-digit county FIPS code
in: query
name: fips
required: true
schema:
type: number
format: integer
- description: 5-digit ZIP Code
in: query
name: zipcode
required: true
schema:
type: number
format: integer
- description: Insurance market
in: query
name: market
required: false
schema:
type: string
enum:
- Individual
- SHOP
- Any
default: Individual
- $ref: '#/components/parameters/year-required'
responses:
'200':
description: Successful response
content:
application/json:
schema:
$ref: '#/components/schemas/RateArea'
summary: Get rate areas
x-summary-source: derived
operationId: getRateAreas
x-operation-id-source: derived
components:
schemas:
Guideline:
properties:
household_size:
description: Total size of household
format: integer
type: number
guideline:
description: Federal poverty level guideline
format: integer
type: number
type: object
LowIncomeChild:
properties:
min_age:
description: Minimum age
format: integer
type: number
max_age:
description: Maximum age
format: integer
type: number
pc_fpl:
description: Percentage federal poverty level
format: float
type: number
type: object
StateMedicaid:
properties:
name:
description: Uppercase name
type: string
abbrev:
description: 2-letter USPS abbreviation
type: string
fiscal_year:
description: 4 digit fiscal year
format: integer
type: number
fiscal_quarter:
description: Fiscal quarter (1 - 4)
format: integer
type: number
pc_fpl_parent:
description: Percentage federal poverty level parent caretaker
format: float
type: number
pc_fpl_pregnant:
description: Percentage medicaid federal poverty level pregnant woman
format: float
type: number
pc_fpl_adult:
description: Percentage federal poverty level adult group
format: float
type: number
pc_fpl_child_newborn:
description: Percentage medicaid federal poverty level child
format: float
type: number
pc_fpl_child_1_5:
description: Percentage medicaid federal poverty level child 1 - 5
format: float
type: number
pc_fpl_child_6_18:
description: Percentage medicaid federal poverty level child 6 - 18
format: float
type: number
low_income_child:
description: Low income child eligibility rules
items:
$ref: '#/components/schemas/LowIncomeChild'
type: array
chip:
description: Children's Health Insurance Program eligibility rules
items:
$ref: '#/components/schemas/LowIncomeChild'
type: array
example:
name: KANSAS
abbrev: KS
fiscal_year: 2019
fiscal_quarter: 1
pc_fpl_parent: 0.33
pc_fpl_pregnant: 1.66
pc_fpl_adult: 0
pc_fpl_child_newborn: 1.66
pc_fpl_child_1_5: 1.49
pc_fpl_child_6_18: 1.33
low_income_child: []
chip:
- min_age: 0
max_age: 18
pc_fpl: 2.35
type: object
MarketplaceModelEnum:
enum:
- FFM
- FFMPartnership
- SBM
- SupportedSBM
type: string
properties: {}
RateArea:
properties:
state:
description: 2-letter USPS abbreviation
type: string
area:
description: Rate area number for the given state.
type: integer
type: object
example:
state: LA
area: 7
County:
properties:
fips:
type: string
example: '04013'
name:
type: string
example: Maricopa County
state:
description: 2-letter USPS state abbreviation
example: AZ
type: string
type: object
ZIPCounty:
properties:
fips:
format: ^[0-9]{5}$
type: string
name:
type: string
state:
format: ^[A-Z]{2}$
type: string
zipcode:
format: ^[0-9]{5}$
type: string
type: object
State:
properties:
abbrev:
description: 2-letter USPS abbreviation
type: string
fips:
description: 2-digit FIPS code
type: string
hix_name:
type: string
hix_url:
format: uri
type: string
marketplace:
$ref: '#/components/schemas/MarketplaceModelEnum'
name:
type: string
shop_hix_name:
type: string
shop_hix_url:
format: uri
type: string
shop_marketplace:
$ref: '#/components/schemas/MarketplaceModelEnum'
8962_link:
format: uri
type: string
8965_link:
format: uri
type: string
assister_program_url:
format: uri
type: string
example:
name: Nevada
abbrev: NV
fips: '32'
marketplace_model: FFM
shop_marketplace_model: FFM
hix_name: Nevada Health Link
hix_url: https://www.nevadahealthlink.com/
shop_hix_name: Nevada Health Link
shop_hix_url: https://www.nevadahealthlink.com/
8962_link: ''
8965_link: ''
assister_program_url: https://www.nevadahealthlink.com/find-assistance/
type: object
PovertyGuideline:
properties:
add_per_person_after_eight:
description: For households over eight members add this value for each additional member
format: integer
type: number
guidelines:
description: Household guidelines
items:
$ref: '#/components/schemas/Guideline'
type: array
type: object
parameters:
zipcode:
description: 5 digit ZIP Code or 1-4 digit prefix of a ZIP Code
in: path
name: zipcode
required: true
x-example: '19123'
schema:
type: string
year-with-default:
x-example: 2019
name: year
description: 4 digit market year (Defaults to the current year when not specified).
in: query
required: false
schema:
type: number
format: integer
apikey:
name: apikey
description: API key used for authentication
in: query
required: true
x-example: d687412e7b53146b2631dc01974ad0a4
schema:
type: string
fips:
description: 5-digit county FIPS code
in: path
name: fips
required: true
x-example: '37057'
schema:
type: string
year-required:
x-example: 2019
name: year
description: 4 digit market year.
in: query
required: true
schema:
type: number
format: integer
securitySchemes:
API_Key:
x-summary: API Key Auth
description: Your API key should be included as a query parameter with the request. You can [fill out this form](https://cms.gov1.qualtrics.com/jfe/form/SV_4N2GHCJfNuX7n8x) to request an API key.
type: apiKey
in: query
name: apikey
x-example: d687412e7b53146b2631dc01974ad0a4