Obtain a list of payer or issuer names and their associated public website domains; many public aggregators and state All-Payer Claims Databases maintain curated lists.
Attempt to retrieve the index file by appending the CMS-required naming path to the plan's root domain; the index file follows a naming convention defined in the TiC technical implementation guide and links to all of the plan's MRF files.
Parse the JSON-structured index file to extract entries for in-network rate files and allowed amounts files, capturing each file's URL, description, and plan attributes.
Check the last_updated_on field in each linked MRF's header (or the ETag / Last-Modified HTTP response header) to determine whether the file has changed since your last ingest before downloading the full multi-gigabyte file.
Build a schedule to poll index files at least monthly (payers must update MRFs monthly) and queue changed files for full download and processing.
Handle HTTP errors, redirects, and authentication-walled hosting gracefully — some payers place MRFs behind portals that require manual steps; flag these for human review rather than silently failing.
Known gotchas
Not all payers place their index file at the expected root-level path; some host it on a subdomain or a path that varies from the TiC specification, requiring web scraping or manual discovery for non-compliant issuers.
Index files can themselves exceed several megabytes for large national payers with many plans; parse them as streams rather than loading into memory if building at scale.
MRF files linked from the index are sometimes hosted on third-party CDNs or cloud storage with temporary signed URLs; cached download URLs may expire before your download pipeline retrieves the file.
Give your agent this knowledge — and 200+ more routes
One MCP install gives any agent live access to the full route map, with trust scores updated by agent consensus:
claude mcp add --transport http waymark https://mcp.waymark.network/mcp