How to Research Foundation Funders Using IRS 990 Data

What Is the "Reverse 990" Method?

Every private foundation in the United States is required to file IRS Form 990-PF annually. These filings are public records, and they contain a goldmine of information for nonprofits seeking funding: a complete list of every grant the foundation awarded that year, including the recipient name, amount, and purpose.

Traditional grant research starts with a foundation and asks "who do they fund?" The reverse method flips this question entirely:

Start with nonprofits similar to yours and ask "who funds them?"

This approach is more efficient because it immediately surfaces foundations with a proven track record of funding organizations in your space. Instead of cold-prospecting through thousands of foundations, you're working with warm leads from day one.

Step-by-Step Walkthrough

Let's walk through a concrete example. Imagine you run a youth mentoring nonprofit in Chicago, Illinois with an annual budget of $500,000. Here's exactly how you'd use the reverse 990 method:

Step 1: Identify 5-10 Similar Organizations

Search for nonprofits that share your characteristics:

• Similar mission: Youth mentoring, after-school programs, or youth development
• Similar geography: Based in Chicago, Illinois, or the broader Midwest
• Similar size: Annual revenue between $200K and $2M

Using Signal990's nonprofit directory for Illinois, you might find organizations like Big Brothers Big Sisters of Metropolitan Chicago, Chicago Youth Programs, or After School Matters.

Step 2: Look Up Their Funders

For each similar nonprofit, examine which foundations have given them grants. On Signal990, you can see this data directly on each nonprofit's profile page. In IRS 990-PF data, look for grants to these specific organizations.

Step 3: Find the Overlap

The foundations that appear most frequently across multiple similar organizations are your strongest prospects. If the same foundation funds three out of five organizations similar to yours, that's a strong signal they're interested in your space.

Step 4: Prioritize and Research

Rank your prospects by overlap count, then dig into each foundation's profile to assess fit. Check their average grant size, geographic focus, and any stated priorities. Signal990's approach path recommendations can help here — for each foundation, you'll see the best way in: direct board connections, co-funding bridges, community entry points, and optimal timing.

Where to Find 990 Data

IRS 990 filings are available from several sources, each with different trade-offs:

Source	Cost	Best For
IRS TEOS	Free	Looking up a specific foundation by EIN
ProPublica Nonprofit Explorer	Free	Browsing individual 990 filings
Signal990	Free / from $399/yr	Automated reverse-lookup, network intelligence, AI research briefs, relationship pipeline
Candid	From $3,499/yr	Deepest data, AI tools, project management, 304K+ funders

The IRS's own tool is free but painful to navigate. ProPublica is better for browsing but doesn't support the reverse-lookup workflow. Signal990 automates the entire process with AI matching, network intelligence, and a relationship pipeline. Candid offers the deepest historical data and is strong for teams focused on data completeness.

Key Data Points in a 990-PF

When reviewing a foundation's 990-PF filing, focus on these sections:

• Part XV — Grant Recipients: The complete list of organizations that received grants, including dollar amounts and brief descriptions of the grant purpose. This is the most valuable section for reverse-lookup research.
• Total Grants Paid (Part I, Line 25): Shows how much the foundation distributes annually. Compare this to total assets to see if they're generous or stingy relative to their size.
• Total Assets (Part II): Indicates the foundation's overall size and long-term giving capacity. By law, most private foundations must distribute at least 5% of assets annually.
• Officers, Directors, and Trustees (Part VIII): Key contacts for outreach. Knowing who sits on the board can help you identify personal connections or shared networks. Signal990's connection paths feature automates this — it maps how your board members connect to any foundation through shared board seats, co-funded organizations, and 2-hop network paths.
• Purpose of Grant: Brief descriptions that reveal the foundation's actual priorities — which can differ from their stated mission on their website.

Common Mistakes to Avoid

Tips for Effective Research

Based on our analysis of thousands of foundation-nonprofit relationships:

• Focus on fit, not size. A $1M foundation that funds organizations exactly like yours is a better prospect than a $1B foundation with no track record in your area.
• Look at multiple years. Foundations that fund the same organizations year after year are more likely to be open to new grantees in that space.
• Check geographic focus. Many foundations limit giving to specific states or regions. Use our state-by-state directory to find local funders.
• Note average grant size. If a foundation typically gives $5,000 grants, don't submit a proposal for $500,000.
• Build a pipeline, not a one-shot list. Grant research is ongoing. Revisit your prospect list quarterly as new 990 data becomes available.

Getting Started

You can start using the reverse 990 method today. Sign up for a free Signal990 account to search 215K+ foundations, run AI-powered funder matching, discover connection paths to foundations through your board, and build dynamic prospect lists. Or browse our foundation directory and nonprofit directory to explore by state.

For more context on which tools are available, see our comparison of grant research tools.