NPI Who

NPI Who MCP server

Look up US health care providers from AI assistants: by NPI, by name, by phone number, by what is near them, and by facility type and state. The server is hosted at https://npiwho.com/mcp (Model Context Protocol, Streamable HTTP). It is free and needs no key.

Every result that names a provider or facility starts with the public page's URL on npiwho.com, so an assistant can cite the page it answered from and send readers there for the detail.

Connect

Nothing to install from this repository. Each client keeps its own list of MCP servers: add the endpoint once in the client you use, then start a new conversation (it does not appear in one that is already open). No account, nothing to sign in to.

Claude Code (terminal), once, in any directory:

claude mcp add --transport http -s user npiwho https://npiwho.com/mcp

-s user makes it available in every project; leave it out for the current project only. claude mcp list should show npiwho as connected. Remove with claude mcp remove -s user npiwho.

Claude.ai (web and desktop): Settings → Connectors → Add custom connector. Name: NPI Who. URL: https://npiwho.com/mcp. Authentication: none. Save, then turn it on in a chat's tools menu.

ChatGPT: Settings → Connectors → Create (developer mode must be on). URL as above, No authentication, save, then enable it for a chat.

Codex (terminal):

codex mcp add npiwho --url https://npiwho.com/mcp

Cursor, Windsurf, VS Code and other clients with a JSON config (mcp.json in this repository):

{
  "mcpServers": {
    "npiwho": { "type": "http", "url": "https://npiwho.com/mcp" }
  }
}

Then ask in plain language: "What do the public records say about NPI 1366487498?", "Who is at (210) 489-7220?", "Which hospices in Austin, Texas are non-profit?" The assistant picks the tool.

Tools

Tool	Returns
lookup_provider	One NPI: the registry record, and what the public files have on the provider (Open Payments total, Medicare billing, OIG exclusion, Medicare clinician record, facility enrollments, claimed-page details), each pointing to the page section with the detail.
search_providers	Individuals or organizations by name, optionally within a state. Up to 20.
lookup_phone	Who lists a given phone number, in any US format.
nearby_providers	The nearest providers of the same specialty, from an NPI or from a ZIP code and taxonomy code.
list_facilities	Medicare-certified home health agencies, hospices, hospitals, nursing homes, or HRSA health centers in a state or city.
data_sources	Which files the answers come from and their snapshot dates.

Try: "What do the public records say about NPI 1366487498?" or "Which hospices in Austin, Texas are non-profit?"

Data

Public federal records joined on the NPI: the NPPES registry (CMS), CMS Open Payments (program years 2019–2025), Medicare Part B and Part D (2024), the HHS-OIG exclusion list, CMS Doctors and Clinicians, Medicare facility enrollments, and HRSA's health center list. File dates are on the methodology page and in the data_sources tool.

None of it is a licence, credential or quality check. Providers can ask for their contact details to be withheld, and those requests apply to the tools exactly as to the pages.

Allowance

About 1,000 tool calls a day per client address, resetting at 00:00 UTC. Calls made through Claude.ai or ChatGPT come from the platform's addresses and share a larger pool. For more, or for bulk work, write to [email protected]. The per-provider payment totals are also an open dataset: npiwho/us-provider-payments.

Who runs it

Derek Hong, Singapore. The server is part of the site; this repository holds its description for the MCP registry and the connection instructions. Issues and questions here or at [email protected].