Halvorsen Family Foundation
The Halvorsen Family Foundation is a private family foundation established in 2000 and based in Stamford, Connecticut. It operates as a 501(c)(3) organization classified under philanthropy, voluntarism, and grantmaking foundations. The foundation takes a highly selective, proactive approach to grantmaking, focusing primarily on organizations with personal connections to the Halvorsen family rather than accepting unsolicited applications.
Key facts about Halvorsen Family Foundation
- EIN
- 06-1603158
- Latest 990 filing
- Form 990-PF, 2025
- Annual giving (2025)
- $34,502,270
- Grants made (2025)
- 33
- Average grant
- $1,045,523
- Median grant
- $20,000
- Primary geography
- California (58% of itemized 2025 grant dollars)
- Accepts unsolicited proposals
- No
- How to apply
- The foundation does not accept unsolicited grant applications. Full details ↓
Data from IRS Form 990-PF, 2025; updated September 2026. Application details from Grantable's research on the foundation's public materials; confirm on its website before applying.
Who Halvorsen Family Foundation funds
By grant dollars, the top recipient states for Halvorsen Family Foundation's 33 itemized 2025 grants were California (58%), New York (20%) and Massachusetts (15%). The most frequent recipient cities were New York, NY (6 grants), Darien, CT (5 grants), Stowe, VT (5 grants) and Williamstown, MA (2 grants). 6% of grants with a stated purpose were for general or operating support. Recurring purposes include "Educational Support" (9 grants), "Medical Support" (7 grants) and "Athletic Opportunities" (5 grants).
How Halvorsen Family Foundation gives
Estimate from itemized IRS Form 990-PF grant lists (2025). Recipient names are matched across years, so a renamed or misspelled grantee can look new; grants to individuals are left out. Methodology.
Next steps with Halvorsen Family Foundation
- How to evaluate Halvorsen Family Foundation as a funder
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Financial Overview
From 2025 IRS Form 990-PF · View filing
Total Assets
—
Annual Giving
$34.5M
+65.2% YoY
Grant Count
33
+83.3% YoY
Avg Grant Size
$1.0M
-9.9% YoY
Mission & Focus Areas
The foundation supports a diverse range of causes including:
- Education (particularly higher education institutions with family connections)
- Arts and culture
- Environmental conservation and biodiversity
- Health and wellness
- Economic justice
- Outdoor recreation
The foundation does not operate formal grant programs with fixed deadlines or public application processes.
Grantmaking
Grant Range
** $10,000 to $20,000,000
Invitation Only
** The foundation does not accept unsolicited grant applications. Grantmaking is invitation-only and highly targeted, with strategic grants made throughout the year to preselected organizations.
Ready to take the next step with Halvorsen Family Foundation?
Geographic Focus
Where this funder awards grants
The foundation primarily funds organizations in Connecticut and surrounding New England states, including:
- Connecticut
- New York
- Massachusetts
- Vermont
- Maine
The foundation has also made limited grants in California, Pennsylvania, Utah, Minnesota, and internationally in Norway and France.
Grant Distribution by State
Share of all 33 itemized 2025 grant dollars.
Cities
Financial History
Multi-year comparison from IRS filings
Total Assets: $322,046,466 (2024)
Annual Revenue: $21,439,948 (2024)
Annual Expenses: $21,087,352 (2024)
Net Income: $352,596 (2024)
Asset Growth: The foundation has grown significantly from initial assets of $16.2 million in 2011 to over $322 million by 2024.
| Metric | 2025 | 2024 | 2023 |
|---|---|---|---|
| Total Assets | — | — | — |
| Revenue | — | — | — |
| Expenses | — | — | — |
| Qualifying Distributions | — | — | — |
| Net Investment Income | — | — | — |
| Distributable Amount | — | — | — |
Data update history
When this profile's IRS filing data changed on Grantable
- IRS filings on file for fiscal years 2020–2025
Giving Over Time
Total grant dollars and number of grants per year
Grant Insights
How this funder distributes its grants
Top Recipients
Top 10 recipients in 2025
Grant Size Distribution
112 grants across all recorded years
Giving History
Grant recipients and amounts by year
Among its reported 2025 grants, the largest recipients include Stanford Medical Development ($20,000,000), Sterling and Francine Clark Art Institute ($5,125,000), Memorial Sloan Kettering Cancer Center ($5,000,000).
| Recipient | Purpose | Amount |
|---|---|---|
| STANFORD MEDICAL DEVELOPMENT Redwood City, CA | EDUCATIONAL SUPPORT | $20,000,000 |
| STERLING AND FRANCINE CLARK ART INSTITUTE Williamstown, MA | ARTISTIC INITIATIVES | $5,125,000 |
| MEMORIAL SLOAN KETTERING CANCER CENTER West Harrison, NY | MEDICAL SUPPORT | $5,000,000 |
| GREEN MOUNTAIN VALLEY SCHOOL Waitsfield, VT | EDUCATIONAL SUPPORT | $1,500,000 |
| WEILL CORNELL MEDICINE New York, NY | MEDICAL SUPPORT | $1,000,000 |
| US SKI & SNOWBOARD Park City, UT | ATHLETIC OPPORTUNITIES | $500,000 |
| WILDLIFE CONSERVATION SOCIETY Bronx, NY | WILDLIFE CONSERVATION | $350,000 |
| THE ROCKEFELLER UNIVERSITY New York, NY | EDUCATIONAL SUPPORT | $275,000 |
| WILLIAMS COLLEGE Williamstown, MA | EDUCATIONAL SUPPORT | $200,000 |
| STANFORD UNIVERSITY Stanford, CA | EDUCATIONAL SUPPORT | $100,000 |
Leadership & Key People
Leadership team and compensation from IRS filings
Trustees:
- Ole Andreas Halvorsen (Co-founder of Viking Global Investors, a Connecticut-based hedge fund firm; born 1961, originally from Norway)
- Diane K. Halvorsen (spouse)
Compensation Overview
No officer or director reported compensation in the available filings.
From 2025 IRS filing
| Name | Title | Hours | Compensation |
|---|---|---|---|
| Ole Andreas Halvorsen | Trustee | 0.3 | — |
| Diane K Halvorsen | Trustee | 0.3 | — |
Contact Information
Address: Viking 600 Washington Blvd, 11th Floor, Stamford, CT 06901
Phone: (203) 863-5039 or (203) 863-5048
Website: The foundation does not maintain a public website and does not provide an email address for inquiries.
Subject Areas
Focus areas based on grantmaking activity
Frequently Asked Questions
What does Halvorsen Family Foundation fund?
The foundation supports a diverse range of causes including: • Education (particularly higher education institutions with family connections) • Arts and culture • Environmental conservation and biodiversity • Health and wellness • Economic justice • Outdoor recreation The foundation does not operate formal grant programs with fixed deadlines or public application processes.
How do I apply for a grant from Halvorsen Family Foundation?
The foundation does not accept unsolicited grant applications. Eligibility and process details are in the grantmaking section of this profile. See how to apply ↑
Where does Halvorsen Family Foundation make grants?
The foundation primarily funds organizations in Connecticut and surrounding New England states, including: • Connecticut • New York • Massachusetts • Vermont • Maine The foundation has also made limited grants in California, Pennsylvania, Utah, Minnesota, and internationally in Norway and France.
What size grants does Halvorsen Family Foundation award?
In 2025, Halvorsen Family Foundation awarded 33 grants totaling $34.5M — an average of about $1.0M per grant, based on its IRS Form 990 filings.
What is Halvorsen Family Foundation's EIN?
Halvorsen Family Foundation's EIN (Employer Identification Number) is 06-1603158. IRS Form 990 filing data is available on this page for 2020–2025.
Does Halvorsen Family Foundation accept unsolicited proposals?
No, according to Grantable's research on the foundation's published guidelines. See how to apply ↑
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Data last updated September 2026. Sourced from IRS Form 990-PF filings. Research dossier generated April 2026.