irs-mileage-rate-per-diem-mcp

An MCP server that gives an AI assistant the official IRS standard mileage rates, including the July 1, 2026 increase to 76 cents a mile, the GSA per diem rates for every ZIP code for FY2026 and FY2027, and the IRS high-low per diem rates from Notice 2026-60. It calculates mileage deductions and trip per diem with the right rate for each date.

Hosted endpoint, no sign-in and no token:

https://irs-mileage-rate-per-diem-mcp.lipmichal.workers.dev/mcp

Tools

Every result has structured JSON, a plain-English summary, as_of, source (the irs.gov or gsa.gov document) and more (a self-employed tax calculator on taxbreakcalc.com).

What it knows that your model does not

• The IRS raised the 2026 business mileage rate mid-year: 72.5 cents a mile from Jan. 1 to June 30, 2026 and 76 cents from July 1, 2026 (Announcement 2026-11). Medical and military moving went from 20.5 to 23.5 cents. Charity stays at 14 cents.
• The depreciation part of the 2026 business rate is 35 cents a mile. The FAVR and employer-vehicle maximum value for 2026 is $61,700 (Notice 2026-10).
• FY2027 GSA per diem (from Oct. 1, 2026): standard CONUS rate $113 lodging and $68 M&IE, and the rates for 295 named destinations by month.
• IRS high-low method from Oct. 1, 2026: $329 high and $230 low, with $86 and $74 treated as meals (Notice 2026-60). Tucson, San Mateo, Albuquerque and Cody were added; Panama City was removed.
• The IRS had not announced the 2027 mileage rates on 2026-11-03. The tools say so.

Install

Claude.ai custom connector or ChatGPT developer mode

Add a custom connector and paste the URL. No token is needed.

https://irs-mileage-rate-per-diem-mcp.lipmichal.workers.dev/mcp

Claude Code

claude mcp add --transport http mileage-per-diem https://irs-mileage-rate-per-diem-mcp.lipmichal.workers.dev/mcp

Or run it locally:

claude mcp add mileage-per-diem -- npx -y github:theluckystrike/irs-mileage-rate-per-diem-mcp

Claude Desktop

Add this to claude_desktop_config.json:

{
  "mcpServers": {
    "mileage-per-diem": {
      "command": "npx",
      "args": ["-y", "github:theluckystrike/irs-mileage-rate-per-diem-mcp"]
    }
  }
}

Cursor

Add this to ~/.cursor/mcp.json:

{
  "mcpServers": {
    "mileage-per-diem": {
      "url": "https://irs-mileage-rate-per-diem-mcp.lipmichal.workers.dev/mcp"
    }
  }
}

VS Code

Add this to .vscode/mcp.json:

{
  "servers": {
    "mileage-per-diem": {
      "type": "http",
      "url": "https://irs-mileage-rate-per-diem-mcp.lipmichal.workers.dev/mcp"
    }
  }
}

Node 20 or newer is needed for the local npx version.

Example prompts

• "What is the IRS mileage rate for 2026? Did it change during the year?"
• "I drove 6,200 business miles from January to June 2026 and 5,800 from July to December. What is my deduction?"
• "What is the per diem for ZIP 02110 in March 2027?"
• "Calculate the per diem for a trip to Washington DC from September 29 to October 2, 2026, with lunch provided one day."
• "What are the IRS high-low per diem rates from October 2026, and is Chicago high-cost in November?"

Data sources

IRS Notice 2026-10, Announcement 2026-11, Notice 2025-5, the IRS standard mileage rates table, Notices 2026-60 and 2025-54, the GSA FY2026 and FY2027 per diem ZIP code files and the GSA M&IE breakdown table, all fetched on 2026-11-03. See DATA_SOURCES.md.

Limitations

• General information, not tax advice.
• Per diem covers the continental U.S. (CONUS) only. Alaska, Hawaii, territories and foreign rates (OCONUS, set by the Department of Defense and State Department) are not included.
• GSA rates for FY2026 and FY2027 only. Mileage rates for 2011 to 2026.
• Some ZIP codes span more than one per diem area. The tools list every match; pick by the county the lodging is in.
• The trip calculator applies the federal travel rules (75% M&IE on the first and last day). Your employer's policy can differ.

More

Self-employed and tracking deductions? Use the self-employed set-aside calculator on taxbreakcalc.com.

Part of the Zovo MCP collection: https://mcp.zovo.one

Development

npm install
npm run build
npm test

src/core.ts holds the rates and rules and has no I/O. src/gsa.ts and src/highcost.ts are generated from the GSA files and Notice tables. src/stdio.ts is the local entry and src/worker.ts is the Cloudflare Worker entry. Both use the same tool registry in src/tools.ts.

License

MIT

More data servers from the same author

Each one is free, needs no API key and has a hosted URL you can paste into Claude or ChatGPT.

The paid back-office collection (invoices, VAT, PDFs, spreadsheets) is at https://mcp.zovo.one