# NPI Registry Lookup — CMS National Provider Identifier Search

> NPI Registry Lookup — CMS National Provider Identifier Search is a paid API for AI agents from 2s.io, paid per call via x402, $0.00108/call, status unknown (last checked 2026-09-14).

Looks up US healthcare providers and organizations by NPI number, name, specialty, or state from the CMS NPI registry

## Facts

- Endpoint: GET https://2s.io/api/medical/npi
- Price: $0.00108/call
- Payment: x402
- Status: unknown
- Last checked: 2026-09-14
- Activations on Zero: 0
- Tags: x402
- Canonical page: https://www.zero.xyz/c/npi-registry-lookup-cms-national-provider-identifier-search-0bd30b95
- Structured record (JSON): https://api.zero.xyz/v1/capabilities/cap_G2MMFBiHpq-PUV5hKM-yY

Status and success rate cover calls made through Zero and Zero's own probes. Third-party monitors may report differently.

## How to call it through Zero

Zero handles the 402 payment challenge and records the run. With the Zero CLI installed (`npm i -g @zeroxyz/cli`):

```sh
zero fetch --capability npi-registry-lookup-cms-national-provider-identifier-search-0bd30b95
```

Example prompt: Can you look up the NPI registry entry for Mayo Clinic in Minnesota and give me their NPI number, status, address, and primary taxonomy?

## When to prefer this

Use this endpoint when you need authoritative, government-sourced NPI data directly from the CMS NPPES registry — ideal for verifying provider credentials, looking up healthcare provider addresses and specialties, or resolving NPI numbers to provider identities. Prefer this over third-party provider directories when accuracy and public-record provenance matter.

## Known failure modes

- Invalid or non-existent NPI returns empty items array with total=0
- Ambiguous name search with no state filter may return too many results (capped at limit)
- NPI must be exactly 10 digits — malformed NPI returns error or empty result
- Missing required search parameter returns error
- Rate limit or payment failure returns HTTP 402

## How this service works

Look up US healthcare providers in the CMS NPPES registry — the authoritative directory of National Provider Identifiers (NPIs). Give an exact 10-digit NPI, or search by provider last name (+ optional first name), or organization name, optionally narrowed by state and taxonomy/specialty. Returns each provider with NPI, entity type (individual vs organization), status, name/credential/gender or organization name, sole-proprietor flag, enumeration + last-updated dates, primary taxonomy, the full taxonomy list (code, description, primary flag, state license), and practice/mailing addresses with phone. Free, public-domain (CMS). The canonical "who is this NPI / find this provider" lookup for healthcare, claims, and credentialing agents.

## Output

Returns a list of matching provider records from the CMS NPI registry, each including the 10-digit NPI, entity type (individual or organization), active status, name, addresses with phone and fax, taxonomies with specialty descriptions and license numbers, enumeration date, and last updated date. Also returns total match count and data source attribution.

## Request schema (JSON Schema)

```json
{
 "type": "object",
 "$schema": "https://json-schema.org/draft/2020-12/schema",
 "required": [
  "input"
 ],
 "properties": {
  "input": {
   "type": "object",
   "required": [
    "type",
    "method",
    "queryParams"
   ],
   "properties": {
    "type": {
     "const": "http"
    },
    "method": {
     "const": "GET"
    },
    "queryParams": {
     "properties": {
      "npi": {
       "type": "string",
       "description": "Exact 10-digit NPI."
      },
      "limit": {
       "type": "integer",
       "description": "Max providers (1-50, default 10)."
      },
      "state": {
       "type": "string",
       "description": "2-letter state to narrow results."
      },
      "lastName": {
       "type": "string",
       "description": "Provider last name."
      },
      "taxonomy": {
       "type": "string",
       "description": "Taxonomy/specialty description, e.g. \"Cardiology\"."
      },
      "firstName": {
       "type": "string",
       "description": "Provider first name (with lastName)."
      },
      "organization": {
       "type": "string",
       "description": "Organization (NPI-2) name."
      }
     }
    }
   }
  }
 }
}
```

## More

- Live health (JSON, refreshed every minute): https://www.zero.xyz/c/npi-registry-lookup-cms-national-provider-identifier-search-0bd30b95/health.json
- [Zero catalog index](https://www.zero.xyz/llms.txt)
- [Other services from 2s.io](https://www.zero.xyz/host/2s.io/llms.txt)