CMS NPI Registry API

cms.gov · Government

Government No Auth Free & Open Government Healthcare Healthcare Government Open Data

Search the National Plan and Provider Enumeration System (NPPES) for healthcare provider NPI numbers. Verify provider credentials, look up practice addresses, specialties, and taxonomy codes. Required for healthcare billing and credentialing workflows.

Authentication

No authentication requiredFree to use with no key needed.

Sample Requests

GET Search provider by name

Returns NPI records matching a provider name. Use organization_name for group practices, first_name/last_name for individuals.

https://npiregistry.cms.hhs.gov/api?limit=10&state=CA&version=2.1&last_name=Smith&first_name=John

Hover any highlighted part to learn what it does

curl -X GET "https://npiregistry.cms.hhs.gov/api/?limit=10&state=CA&version=2.1&last_name=Smith&first_name=John"

import requests
params = {
    "limit": "10",
    "state": "CA",
    "version": "2.1",
    "last_name": "Smith",
    "first_name": "John"
}
response = requests.get(
    "https://npiregistry.cms.hhs.gov/api/",
    params=params,
)
print(response.json())

const url = new URL('https://npiregistry.cms.hhs.gov/api/');
url.searchParams.set('limit', '10');
url.searchParams.set('state', 'CA');
url.searchParams.set('version', '2.1');
url.searchParams.set('last_name', 'Smith');
url.searchParams.set('first_name', 'John');

const response = await fetch(url); 
const data = await response.json();
console.log(data);

package main

import (
	"fmt"
	"io"
	"net/http"
	"net/url"
)

func main() {
	baseURL, _ := url.Parse("https://npiregistry.cms.hhs.gov/api/")
	q := baseURL.Query()
	q.Set("limit", "10")
	q.Set("state", "CA")
	q.Set("version", "2.1")
	q.Set("last_name", "Smith")
	q.Set("first_name", "John")
	baseURL.RawQuery = q.Encode()
	targetURL := baseURL.String()
	req, _ := http.NewRequest("GET", targetURL, nil)

	client := &http.Client{}
	resp, _ := client.Do(req)
	defer resp.Body.Close()
	body, _ := io.ReadAll(resp.Body)
	fmt.Println(string(body))
}

require "net/http"
require "json"

uri = URI("https://npiregistry.cms.hhs.gov/api/")
uri.query = URI.encode_www_form({
  "limit" => "10",
  "state" => "CA",
  "version" => "2.1",
  "last_name" => "Smith",
  "first_name" => "John"
})

http = Net::HTTP.new(uri.host, uri.port)
http.use_ssl = uri.scheme == "https"

req = Net::HTTP::Get.new(uri)

res = http.request(req)
puts JSON.parse(res.body)

<?php
$url = "https://npiregistry.cms.hhs.gov/api/?" . http_build_query([
    "limit" => "10",
    "state" => "CA",
    "version" => "2.1",
    "last_name" => "Smith",
    "first_name" => "John"
]);
$opts = ["http" => [
    "method" => "GET",
]];
$ctx = stream_context_create($opts);
$res = file_get_contents($url, false, $ctx);
print_r(json_decode($res, true));

GET Look up by NPI number

Returns full provider record for a known NPI number.

https://npiregistry.cms.hhs.gov/api?number=1003000126&version=2.1

Hover any highlighted part to learn what it does

curl -X GET "https://npiregistry.cms.hhs.gov/api/?number=1003000126&version=2.1"

import requests
params = {
    "number": "1003000126",
    "version": "2.1"
}
response = requests.get(
    "https://npiregistry.cms.hhs.gov/api/",
    params=params,
)
print(response.json())

const url = new URL('https://npiregistry.cms.hhs.gov/api/');
url.searchParams.set('number', '1003000126');
url.searchParams.set('version', '2.1');

const response = await fetch(url); 
const data = await response.json();
console.log(data);

package main

import (
	"fmt"
	"io"
	"net/http"
	"net/url"
)

func main() {
	baseURL, _ := url.Parse("https://npiregistry.cms.hhs.gov/api/")
	q := baseURL.Query()
	q.Set("number", "1003000126")
	q.Set("version", "2.1")
	baseURL.RawQuery = q.Encode()
	targetURL := baseURL.String()
	req, _ := http.NewRequest("GET", targetURL, nil)

	client := &http.Client{}
	resp, _ := client.Do(req)
	defer resp.Body.Close()
	body, _ := io.ReadAll(resp.Body)
	fmt.Println(string(body))
}

require "net/http"
require "json"

uri = URI("https://npiregistry.cms.hhs.gov/api/")
uri.query = URI.encode_www_form({
  "number" => "1003000126",
  "version" => "2.1"
})

http = Net::HTTP.new(uri.host, uri.port)
http.use_ssl = uri.scheme == "https"

req = Net::HTTP::Get.new(uri)

res = http.request(req)
puts JSON.parse(res.body)

<?php
$url = "https://npiregistry.cms.hhs.gov/api/?" . http_build_query([
    "number" => "1003000126",
    "version" => "2.1"
]);
$opts = ["http" => [
    "method" => "GET",
]];
$ctx = stream_context_create($opts);
$res = file_get_contents($url, false, $ctx);
print_r(json_decode($res, true));

Postman Setup Guide

Get Postman ↗

No API key needed — completely open
GET https://npiregistry.cms.hhs.gov/api/?version=2.1&{filters}
For individuals: use first_name, last_name, state, taxonomy_description
For organizations: use organization_name, state
enumeration_type=NPI-1 (individual) or NPI-2 (organization)
Response includes addresses, taxonomy codes, and credential status
Max 1,200 results per request — use skip parameter to paginate

What can you build with CMS NPI Registry API?

CMS NPI Registry API is a Government API. Developers commonly use government APIs for:

surfacing public datasets in citizen-facing apps
building transparency and civic engagement tools
accessing legislation, court records, and official data
powering research and journalism tools
creating compliance and regulatory monitoring dashboards

No authentication required. This API is open — no signup or key needed. Ideal for quick prototypes and public-facing features. CMS NPI Registry API is free to use, making it a low-risk choice to experiment with.

New to APIs? Read our beginner's guide · Learn about API keys · What is REST?

Open documentation ↗