IRS Nonprofit Lookup MCP Server

IRS Nonprofit Lookup

Official IRS registry of every tax-exempt organization in the United States — 1.9M+ organizations across all 501(c) subsections. Updated daily from the IRS Exempt Organizations Business Master File (EO BMF).

Free, no API key required.

Data Source

The IRS publishes the Exempt Organizations Business Master File as public CSV extracts containing every organization that has received a determination letter recognizing its tax-exempt status. This includes 501(c)(3) charities, 501(c)(4) social welfare organizations, 501(c)(6) business leagues, and all other exempt subsections.

Capabilities

• EIN lookup — exact match by Employer Identification Number. Returns full organization details.
• Name search — fuzzy matching ranked by similarity score; optional sort_by=assets orders by assets with a higher default similarity floor unless min_match_score is set. Responses include min_match_score_applied so you can see which floor was used. Filter by state, city, or subsection code.
• Location search — browse organizations by state, city, or ZIP code, ranked by asset size.
• 501(c)(3) verification — confirm whether an EIN is a valid, active 501(c)(3) with deductibility and foundation classification.
• Reference codes — list all IRS classification code tables (subsection codes, NTEE categories, deductibility, foundation types, exempt status). Call this to discover valid filter values or interpret codes in results.
• Dataset statistics — total records, active count, breakdowns by subsection, data freshness.

Search results return compact summaries (EIN, name, city, state, subsection, deductibility, NTEE code, assets, income). Use EIN lookup for the full record with address, foundation code, ruling date, revenue, activity codes, and all classification fields.

Financial Data

asset_amount, income_amount, and revenue_amount are in whole dollars (not thousands). Example: asset_amount: 4578219874 = $4.578 billion.

Key Fields

• EIN — Employer Identification Number (XX-XXXXXXX format)
• subsection / subsection_label — IRS code section + human-readable description
• deductibility_code / deductibility_label — whether contributions are tax-deductible
• foundation_code / foundation_label — 509(a) classification (public charity vs private foundation) — detail view only
• ruling_date — when the IRS granted exempt status (YYYY-MM format)
• ntee_code / ntee_category — NTEE classification code + major category label
• exempt_status_code / exempt_status — current IRS exemption status + label

Workflows

Donor due diligence: Search by name → pick the matching organization → verify 501(c)(3) status by EIN → confirm deductibility and active status.

Nonprofit research: Use the reference codes tool to discover subsection and NTEE codes → search by location with the appropriate filter → rank by asset size.

Sector analysis: Use location search with subsection filter → compare organization counts and asset sizes across cities or states.