Unofficial US Commercial Insurance Formulary MCP Server

Model Context Protocol (MCP) server providing unified access to drug formulary data from US ACA marketplace health insurance plans.

Features

Unified drug search across ~15,000 plans from ~735 issuers
Coverage details: tier levels, copays, coinsurance
Restriction info: prior authorization, step therapy, quantity limits
Plan comparison: compare drug coverage across plans
State filtering: filter results by state
Full-text search: fast drug name search with FTS5

Installation

cd formulary-mcp-server
npm install

Option 1: Download Pre-built Database

npm run download:db

Option 2: Build Database from Source

# Download issuer index from CMS
npm run download:index

# Download formulary files for all issuers
npm run download:files

# Build SQLite database
npm run build:db

Build and Run

npm run build
npm start

Usage

{
  "mcpServers": {
    "formulary": {
      "command": "node",
      "args": ["/path/to/formulary-mcp-server/build/index.js"]
    }
  }
}

Tool: formulary_info

Single unified tool with multiple methods:

Methods

| Method | Description | Required Params | |--------|-------------|-----------------| | search_drug | Search drugs by name | drug_name | | get_drug_details | Get full drug info with coverage | rxnorm_id | | get_plan_formulary | Get drugs covered by a plan | plan_id | | get_plan_details | Get plan info and tier structure | plan_id | | compare_coverage | Compare drug across plans | rxnorm_id | | search_plans | Search plans by state/issuer | - | | get_restrictions | Get PA/ST/QL requirements | rxnorm_id | | get_alternatives | Find drugs in same tier | rxnorm_id, plan_id | | get_statistics | Get database statistics | - |

Example Usage

Search for a drug: ``json { "method": "search_drug", "drug_name": "metformin", "state": "CA", "limit": 10 } ``

Get drug details: ``json { "method": "get_drug_details", "rxnorm_id": "860975", "state": "CA" } ``

Compare coverage: ``json { "method": "compare_coverage", "rxnorm_id": "860975", "state": "TX", "limit": 20 } ``

Get plan formulary: ``json { "method": "get_plan_formulary", "plan_id": "12345VA0010001", "tier": "GENERIC" } ``

Get restrictions: ``json { "method": "get_restrictions", "rxnorm_id": "860975", "plan_id": "12345VA0010001" } ``

Response Format

Drug Search Response

{
  "method": "search_drug",
  "query": "metformin",
  "count": 5,
  "results": [
    {
      "rxnorm_id": "860975",
      "drug_name": "Metformin Hydrochloride 500 MG Oral Tablet",
      "plan_count": 245,
      "tiers": ["GENERIC", "PREFERRED-BRAND"]
    }
  ]
}

Drug Details Response

{
  "method": "get_drug_details",
  "drug": {
    "rxnorm_id": "860975",
    "drug_name": "Metformin Hydrochloride 500 MG Oral Tablet"
  },
  "coverage_summary": {
    "total_plans": 245,
    "plans_with_pa": 12,
    "plans_with_st": 5,
    "plans_with_ql": 89
  },
  "coverage": [
    {
      "plan_id": "12345CA0010001",
      "drug_tier": "GENERIC",
      "prior_authorization": false,
      "step_therapy": false,
      "quantity_limit": true,
      "marketing_name": "Blue Shield Gold",
      "issuer_name": "Blue Shield of California",
      "copay_amount": 10.00,
      "coinsurance_rate": 0.20
    }
  ]
}

Data Coverage

| Aspect | Coverage | |--------|----------| | Plans | ~5,500 ACA marketplace plans | | Issuers | ~150 insurance companies | | Drugs | ~13,000 unique medications | | Templates | ~800 unique formulary templates | | States | 15+ states | | Data | Tier, PA, step therapy, quantity limits |

Data Source

Data is sourced from the CMS QHP (Qualified Health Plan) Provider & Formulary APIs:

https://github.com/CMSgov/QHP-provider-formulary-APIs
https://data.healthcare.gov/

Note: This covers ACA marketplace plans only. Employer-sponsored and Medicare Advantage plans are not included.

License

MIT

Formulary MCP Server