---
title: "Resolve a 10-digit NPI to the provider identity plus a..."
method: GET
path: "/api/medical/provider-id-resolve"
tags: ["medical"]
---

# Resolve a 10-digit NPI to the provider identity plus a...

`GET /api/medical/provider-id-resolve`

## Request

- Base URL: `https://2s.io`
- URL: `https://2s.io/api/medical/provider-id-resolve`
- Auth: API key in header `PAYMENT-SIGNATURE`

Resolve a 10-digit NPI to the provider identity plus a fully decoded specialty profile in one call: entity type, name/organization, status, the primary specialty (NUCC grouping + classification + display name), and every taxonomy on the record decoded the same way -- with primary flag, practice state, and license. Combines the NPPES lookup (medical.npi) with the NUCC specialty decode (medical.taxonomy-specialty) so a claims, credentialing, or referral agent gets "who is this NPI and what do they actually do" without a second call. Data: CMS NPPES + NUCC (US public domain). Note: the facility CCN (CMS Certification Number) requires a separate CMS enrollment crosswalk and is returned null (DEFERRED) rather than guessed.

## Query parameters

- `npi` string, required
- `trial` 1

## Other responses

- `200` (unresolved $ref)
- `400`: Invalid request — not charged. error.code: BAD_REQUEST or INVALID_PARAM (parameter validation; error.details.issues lists each problem), MALFORMED_JSON, or a request-specific code. Other client errors: 405 METHOD_NOT_ALLOWED (wrong verb; see the Allow header), 413 PAYLOAD_TOO_LARGE.
- `402`: Payment required. Body is the x402 PaymentRequirements envelope with a multi-network accepts array; the per-call price is in accepts[].amount (and on the operation as x-2s-price). Sign for whichever rail you hold USDC on (EIP-3009 for Base, partial SPL transfer for Solana) and retry with the PAYMENT-SIGNATURE header (X-PAYMENT also accepted for v1 clients). Also PAYMENT_SETTLE_FAILED (error envelope) when a verified payment failed to settle: error.details.chargeStatus is "not_charged" (retry with a fresh payment) or "unknown" (the authorization may still settle before its deadline — check it before retrying).
- `404`: Not found — NOT_FOUND (or NO_SOURCES / NO_OPINIONS): the requested entity does not exist. Not charged.
- `429`: Too many requests — RATE_LIMITED: our per-IP / per-payer limiter. Not charged; retry after Retry-After.
- `5XX`: Server-side failure. 500 INTERNAL: unexpected error; quote error.errorId (also the X-2s-Error-Id header). 502 UPSTREAM_UNAVAILABLE (or another UPSTREAM_* code): the data provider failed — composite endpoints refuse unbilled when every source fails. 503 SERVICE_PAUSED: endpoint paused by the operator kill switch, retry after Retry-After; 503 SPEND_CAP: daily upstream budget exhausted. 504 UPSTREAM_TIMEOUT. Not charged.

---

[API](https://skmtc.dev/2s-io/apis/2s-the-most-everything-api.md) · [All operations](https://skmtc.dev/2s-io/apis/2s-the-most-everything-api/llms.txt) · [OpenAPI document](https://skmtc.dev/2s-io/apis/2s-the-most-everything-api/revisions/da4c5caf686e?raw)