
medical-codes-mcp-server
Offline US medical code lookup and crosswalk — ICD-10-CM/PCS, HCPCS Level II, RxNorm.
What it can do
What data it sees
Do you need an account
No: the server works without sign-in
Offline US medical code lookup and crosswalk — ICD-10-CM/PCS, HCPCS Level II, RxNorm. Keyless.
How to connect
How to connect medical-codes-mcp-server to Claude
The server address to paste into Claude settings:
https://medical-codes.caseyjhand.com/mcp
- Open Claude (claude.ai or the desktop app).
- Go to Settings → Connectors.
- Click Add custom connector.
- Paste the server address copied below into Remote MCP server URL and click Add.
- In a chat, click + → Connectors and switch the new connector on.
Custom connectors are available on Free, Pro, Max, Team and Enterprise plans (Free is limited to one). On Team and Enterprise an organization Owner adds the connector first under Organization settings → Connectors.
Authorization
After you click Add, a sign-in window for the service opens. Sign in with your own account and approve access. Claude never sees your password.
How to connect medical-codes-mcp-server to ChatGPT
The server address to paste into ChatGPT settings:
https://medical-codes.caseyjhand.com/mcp
- Open ChatGPT in a browser (chatgpt.com). A Plus, Pro, Business, Enterprise or Edu plan is required.
- Turn on developer mode once: Settings → Apps → Advanced settings → Developer mode.
- Open Settings → Connectors and click Create.
- Fill in the form: Name (anything), Description (one line about what the service does), MCP server URL (copy it below).
- Under Authentication choose OAuth if the service requires sign-in, otherwise None. Click Create.
- In a new chat open + → Apps/Connectors and enable the connector.
OpenAI has renamed this section before (Connectors → Apps/Plugins). If the label differs, search settings for "developer mode". On Business/Enterprise workspaces an admin must allow custom connectors first.
Authorization
On first use ChatGPT opens the service's sign-in window. Sign in and approve access.
How to connect medical-codes-mcp-server to Cursor
The server address to paste into Cursor settings:
https://medical-codes.caseyjhand.com/mcp
Fastest: click Open in Cursor below and confirm the prompt.
Manually:
- In Cursor open Settings → Cursor Settings → MCP and click Add new global MCP server.
- Paste the JSON copied below into
~/.cursor/mcp.json(per project:.cursor/mcp.jsonin the repo root). - Save the file. The server appears in the MCP list; authorize it there if asked.
Authorization
If the service needs sign-in, an authorize button appears next to the server in the MCP list.
Server tool list (6)
Raw names from tools/list. Only developers need these.
| medcode_get_code | Decode one or more US medical codes to their official descriptions across ICD-10-CM (diagnoses), ICD-10-PCS (inpatient procedures), HCPCS Level II (supplies/drugs/services), and RxNorm (drugs, by RXCUI). Also decodes a National Drug Code (NDC) directly to its RxNorm product offline, tagged `source: "NDC"` — hyphenated in an FDA segment configuration (4-4-2, 5-3-2, 5-4-1, or the 11-digit 5-4-2) or as bare 10/11 digits; any other segment widths are malformed and stay unresolved. Auto-detects the system from each code's shape; pass an explicit `system` only when a value is genuinely ambiguous. Accepts 1–50 codes and returns partial success: resolved codes in `found`, unresolved in `notFound` with a per-code reason, so one bad code never fails the batch. Set `includeHierarchy` to attach each code's parent and immediate children (with a `childrenTruncated` flag when a code has more children than the cap returns — walk the full set via medcode_browse_hierarchy or medcode_map_codes). The resolved `system` is echoed on every result for chaining into medcode_map_codes or a billability check; a code string that also exists in another bundled system carries `alsoInSystems` naming it, so a single answer to a colliding code is never mistaken for the only one. |
| medcode_search_codes | Find US medical codes whose official descriptions match a described concept, via full-text search over the bundled index. Every search term must appear — matched first as a token prefix, then as a substring so inflected and compound forms are also found (a "neuropathy" search surfaces "mononeuropathy"/"polyneuropathy" siblings too, not only a standalone "neuropathy" token). Filter by `system` (ICD10CM/ICD10PCS/HCPCS/RXNORM), `billableOnly` to exclude headers/categories, and `chapter`. Use when you have a clinical description and need the code — the reverse of medcode_get_code. Results echo the resolved system per row for chaining, rank exact prefix matches ahead of substring-only matches with a deterministic tie-break, and disclose truncation with a `nextCursor`: pass it back as `cursor` to page through the full ranked set. |
| medcode_check_code | Validate whether a US medical code exists, is current, and is billable in the active bundled release. Returns a discriminated status — valid_billable, valid_not_billable, valid_header, or terminated — with a `whyNot` explaining non-billable and terminated cases (e.g. "valid ICD-10-CM category but not billable — submit a more specific child code"). This is the detail a coder needs before submitting a claim. Auto-detects the system from the code's shape; pass an explicit `system` to disambiguate. A non-billable or terminated code is a successful result with a whyNot, not an error — only a code that exists in no bundled system raises unknown_code. A code string that also exists in another bundled system carries `alsoInSystems` naming it, since the verdict applies only to the system that answered. |
| medcode_map_codes | Crosswalk a US medical code or drug across systems and within a hierarchy. Hierarchy directions: `parents` and `children` walk a code's prefix hierarchy one level per call — immediate parent/children only (depth-1); call iteratively for the full ancestor or descendant path (ICD-10-CM/HCPCS; ICD-10-PCS codes have no prefix parent). A resolvable source with no edge in the requested direction is a successful empty result with a notice, not an error. A source code string that also exists in another bundled system carries `alsoInSystems` naming it, since only the resolved system's hierarchy was walked. Drug directions (RxNorm): `name_to_rxcui` (drug name → RXCUI), `ndc_to_rxcui` and `rxcui_to_ndc` (NDC ↔ RXCUI; NDCs accepted hyphenated in an FDA segment configuration — 4-4-2, 5-3-2, 5-4-1, or the 11-digit 5-4-2 — or as bare 10/11 digits; `ndc_to_rxcui` names the product it decoded to), `rxcui_to_ingredients` and `rxcui_to_brands` (RXCUI → ingredient/brand RXCUIs, each with the target's RxNorm name and its `conceptType` — read that before counting a combination product's ingredients). Every result carries `source` provenance (which system or edge answered) so a chained call (e.g. into openfda with a resolved NDC) uses the right identifier. The `children`, `name_to_rxcui`, and `rxcui_to_ndc` directions can return large sets and paginate: a `nextCursor` in the response is passed back as `cursor` (with an optional `limit` page size) to walk the full set; the point directions ignore both. |
| medcode_browse_hierarchy | Walk a US medical code system's hierarchy for discovery without a search term. With no `node`, returns the top-level entries (ICD-10-CM categories, HCPCS range buckets, or ICD-10-PCS first-axis values). With a `node`, returns its immediate children. ICD-10-CM and HCPCS use a prefix hierarchy (a shorter code is the parent of a longer one); ICD-10-PCS is axis-based — each of its 7 characters is an independent axis (section, body system, root operation, body part, approach, device, qualifier), but only the top-level Section axis is browsable (omit `node`): positions 2–7 are context-dependent on the preceding axis path and are not enumerable from a flat partial code. Lets an agent orient in an unfamiliar system or enumerate a category's specific codes. A large child set paginates: when the response carries a `nextCursor`, pass it back as `cursor` to fetch the next page. |
| medcode_list_systems | List the bundled US medical code systems with their release identifiers, effective dates, and code counts. Confirms which ICD-10-CM fiscal year, ICD-10-PCS fiscal year, HCPCS Level II release, and RxNorm normalized set are active before acting on any decode, search, or crosswalk result. The corpus is offline and built at package-build time — this call reports exactly which release is baked into the running server. ICD-10-CM/PCS are the US clinical modifications, not the ICD-10/ICD-11 base. |