US 501(c) nonprofit organization search. Lookup by 9-digit EIN (with or without hyphen), free-text name, 2-letter state, NTEE category code (e.g. 'B99' for education), or IRS subsection code (3 = 501(c)(3), 4 = 501(c)(4), etc.). Each record includes EIN, name, city/state, NTEE code, subsection code + human-readable subsection description (e.g. '501(c)(3) Charitable / Religious / Educational'), and relevance score. Sourced from ProPublica Nonprofit Explorer, which aggregates IRS Form 990 + BMF data; underlying IRS data is public domain.