Additional Ventures Foundation
Additional Ventures Foundation is a private foundation based in Palo Alto, California, that supports biomedical research aimed at curing single ventricle heart disease. It funds research and related initiatives intended to improve understanding, treatment, and care for people with the condition.
Additional Ventures Foundation at a glance
In short: Additional Ventures Foundation gave $17.2M across 68 grants in 2024 (avg $252K), top state California. Source: 2024 IRS Form 990-PF.
- Annual giving (2024)
- $17,151,264
- +3.6% vs 2023
- Grants made (2024)
- 68
- -13.9% vs 2023
- Average grant
- $252,224
- +20.4% vs 2023
- Median grant
- $220,000
- Total assets
- $220,336,715
- +6.9% vs 2023
- Primary geography
- California (30% of itemized 2024 grant dollars)
- Latest 990 filing
- Form 990-PF, 2024 View filing
Data from IRS Form 990-PF, 2024; updated October 2026.
How to apply to Additional Ventures Foundation
- Accepts unsolicited proposals
- No
- How to Apply
-
The foundation states that it makes contributions only to preselected charitable organizations and does not accept unsolicited requests for funds.
- Contact
Mailing address: 314 Lytton Ave, Palo Alto, CA 94301
Phone: (650) 804-7100
Website: https://additionalventures.org
Application details from Grantable's research on the foundation's public materials; confirm on its website before applying.
Open Grants
5 open opportunities from Additional Ventures Foundation
Expansion Award Grant
Additional Ventures Foundation
Amount
Up to US $50,000
Deadline
Deadline not published
Expansion Award Program
Additional Ventures Foundation
Amount
$50,000
Deadline
Deadline not published
Outstanding Research Presentation Award
Additional Ventures Foundation
Amount
Varies
Deadline
Deadline not published
Who Additional Ventures Foundation funds
How this funder distributes its grants
Top Recipients
Top 10 recipients in 2024
The largest 2024 recipient was The J David Gladstone Institutes ($1.3M across 2 grants). Together the top 10 received $8.7M.
Organizations only. It also paid 1 grant to individuals ($247,933), which are not listed by name.
Grant Size Distribution
258 grants across all recorded years
The most common grant size was in the $100–250K range: 167 grants of 258 (65%).
Geographic Focus
Where this funder awards grants
The 2024 filing lists grant recipients in multiple states. California accounted for 30% of grant dollars, Massachusetts 9%, Pennsylvania 9%, and Ohio 9%; the filing also lists 13% for an unspecified state category.
Grant Distribution by State
Share of 2024 grant dollars across all 68 itemized grants.
States
Cities
How Additional Ventures Foundation gives
- 74% of 2024 grantees were also funded in 2023. Method
- Giving grew 107% from 2021 to 2024. Method
- In 2024 it paid out 184% of its IRS minimum distribution (the 5% rule). Method
Estimate from itemized grant lists in IRS Form 990-PF filings (2024). Recipient names are matched across years, so a renamed or misspelled grantee can look new; grants to individuals are left out. Methodology.
Giving History
Giving Over Time
Total grant dollars and number of grants per year
From 2020 to 2024, annual grant giving ranged from $4.0M (2020) to $17.2M (2024). In 2024 it made 68 grants totaling $17.2M.
Grants by year
Grant recipients and amounts by year
| Recipient | Purpose | Amount |
|---|---|---|
| The J David Gladstone Institutes San Francisco, CA | Innovation Award | $1,200,000 |
| Renata Medical Inc Newport Beach, CA | Transcatheter Fontan Shunt Development | $1,100,000 |
| Boston Children's Hospital Boston, MA | Force Fund | $934,317 |
| Nationwide Children's Hospital Inc Columbus, OH | Cures Collaborative | $594,872 |
| Carnegie Mellon University Pittsburgh, PA | Cures Collaborative | $493,452 |
| Washington University in St Louis St. Louis, MO | Cures Collaborative | $381,383 |
| The Board of Trustees of the Leland Stanford Junior University Redwood City, CA | Cures Collaborative | $322,050 |
| Emory University Atlanta, GA | Cures Collaborative | $302,993 |
| Irccs Azienda Ospedaliero Universitaria Di Bologna | Single Ventricle Research Fund | $295,918 |
| The Rector & Visitors of the University of Virginia Charlottesville, VA | Single Ventricle Research Fund | $282,614 |
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Financial History
Multi-year comparison from IRS filings
| Filing year | Total Assets | Revenue | Expenses | Grants paid | Grants | Qualifying Distributions | Net Investment Income | Distributable Amount |
|---|---|---|---|---|---|---|---|---|
| 2024 | $220,336,715 | $29,136,428 | $19,505,047 | $17,151,264 | 68 | $20,058,316 | $18,414,641 | $10,904,319 |
| 2023 | $206,084,034 | $39,091,290 | $26,204,199 | $16,550,146 | 79 | $19,156,209 | $38,387,473 | $9,347,319 |
| 2022 | $180,921,457 | $19,582,543 | $10,587,777 | $11,920,946 | 64 | $14,675,069 | $5,348,026 | $8,834,497 |
| 2021 | $212,172,958 | $30,400,000 | $24,850,642 | $8,270,706 | 41 | $9,783,419 | $17,892,315 | $9,679,284 |
| 2020 | $175,487,786 | $24,311,033 | $9,831,900 | $3,952,577 | 6 | — | $13,212,342 | $7,179,840 |
Under IRS private-foundation payout rules, Additional Ventures Foundation reported a distributable amount of $10.9M for 2024 — the minimum it must pay out in qualifying distributions.
Research compiled by Grantable AI from public sources. Last updated October 2026.
Mission & Focus Areas
Additional Ventures’ mission is to cure single ventricle heart disease through transformative research and strategic investments that revolutionize treatment and care. Its website identifies a focus on single ventricle defects, biomarkers, sequelae, and related comorbidities. Its 2026 Research Roadmap centers on restoring pump function, addressing complications of single ventricle and Fontan physiology, and understanding differences in patient biology.
The foundation’s grants support a range of organizations, including research institutes, universities, and hospitals. For example, grantee Gladstone Institutes describes its mission as advancing discovery in disease-oriented science and mentoring future leaders. Carnegie Mellon University describes an educational and university-community mission, while Cincinnati Children’s Hospital Medical Center says it aims to improve child health through research, education, and care.
Grantmaking
In filing year 2024, the foundation reported 68 grants totaling $17,151,264. Grant amounts ranged from $2,500 to $1,200,000, with a median of $220,000. Its larger awards included $1,200,000 to the J David Gladstone Institutes for an Innovation Award, $1,100,000 to Renata Medical Inc. for transcatheter Fontan shunt development, and $934,317 to Boston Children’s Hospital for the Force Fund. Other listed awards included $594,872 to Nationwide Children’s Hospital and $493,452 to Carnegie Mellon University, both for the Cures Collaborative.
The foundation’s website describes the Single Ventricle Research Fund as its flagship annual program. It has Independent Investigator and Career Development tracks, with applicants able to request up to $600,000 or $300,000 in direct costs, respectively, over three years. The website also describes the 2027 cycle as open. The Catalyst to Independence Award supports early-career scientists transitioning from mentored postdoctoral positions to independent faculty roles; the listed deadline of March 16, 2026, has passed. The Expansion Award provides a one-time award of up to $50,000 for new single ventricle research directions.
Leadership & Key People
Leadership team and compensation from IRS filings
The 2024 filing lists Erin Hoffmann as president, chairman, and director; Michael Schroepfer as CFO and director; and Tom Van Loben Sels as secretary. The foundation’s website identifies Hoffmann as executive chairman and founder, Schroepfer as founder, and Kirstie Keller as CEO.
Additional Ventures Foundation is led by Kirstie Keller, CEO on the 2024 filing; 1 of 4 officers listed in 2024 is compensated.
Officers on the 2024 filing
Kirstie Keller
CEO
New on the 2024 filing
40 hrs/week
$310K (2024)
Erin Hoffmann
President, Chairman & Director
On filings since 2020
6 hrs/week
No compensation reported
Michael Schroepfer
CFO & Director
On filings since 2020
1 hr/week
No compensation reported
Tom Van Loben Sels
Secretary
On filings since 2020
1 hr/week
No compensation reported
Data from IRS Form 990 filings, 2020–2024. "On filings since" is the earliest filing we hold that lists the person; hours are average hours per week as reported.
Compensation Overview
From 2024 IRS filing
The highest reported compensation on the 2024 filing was $310K, to Kirstie Keller (CEO).
Frequently asked questions about Additional Ventures Foundation
How much does Additional Ventures Foundation give each year?
Additional Ventures Foundation gave $17.2M across 68 grants in 2024, according to its 2024 IRS Form 990-PF. In 2023 it gave $16.6M across 79 grants.
What is Additional Ventures Foundation's typical grant size?
Additional Ventures Foundation's median grant in 2024 was $220,000, and its average grant was $252,224, across 68 grants on its 2024 IRS Form 990-PF.
Where does Additional Ventures Foundation give grants?
Additional Ventures Foundation's top state is California, with 30% of the grant dollars itemized on its 2024 IRS Form 990-PF. The next largest states were Massachusetts (9%) and Pennsylvania (9%). The most frequent recipient cities were Boston, MA (4 grants), Redwood City, CA (4 grants), New York, NY (4 grants) and Philadelphia, PA (4 grants).
Does Additional Ventures Foundation give general operating support?
Not in 2024: none of the 68 grants with a stated purpose on Additional Ventures Foundation's 2024 IRS Form 990-PF were described as general or operating support. Recurring purposes include "Single Ventricle Research Fund" (45 grants), "Cures Collaborative" (8 grants) and "Catalyst to Independence Award" (6 grants).
Who are Additional Ventures Foundation's largest grantees?
Additional Ventures Foundation's largest 2024 grantees include The J David Gladstone Institutes ($1,345,098 across 2 grants), Boston Children's Hospital ($1,279,662 across 3 grants) and Renata Medical Inc ($1,230,000 across 2 grants), according to its 2024 IRS Form 990-PF. It also paid 1 grant to individuals ($247,933), which are not listed by name. Together they received 22% of its itemized 2024 grant dollars.
How large is Additional Ventures Foundation?
Additional Ventures Foundation reported $220.3M in total assets on its 2024 IRS Form 990-PF. It paid out $20.1M in qualifying distributions that year, against a required minimum of $10.9M (roughly 5% of its investment assets).
What does Additional Ventures Foundation fund?
Additional Ventures’ mission is to cure single ventricle heart disease through transformative research and strategic investments that revolutionize treatment and care. Its website identifies a focus on single ventricle defects, biomarkers, sequelae, and related comorbidities. See mission & focus areas ↑
How do I apply for a grant from Additional Ventures Foundation?
The foundation states that it makes contributions only to preselected charitable organizations and does not accept unsolicited requests for funds. Eligibility and process details are in the grantmaking section of this profile. See how to apply ↑
What is Additional Ventures Foundation's EIN?
Additional Ventures Foundation's EIN (Employer Identification Number) is 81-4429034. IRS Form 990 filing data is available on this page for 2020–2024.
Does Additional Ventures Foundation accept unsolicited proposals?
No, according to Grantable's research on the foundation's published guidelines. See how to apply ↑
Data last updated October 2026. Sourced from IRS Form 990-PF filings. Research dossier generated October 2026.
Data update history
(1)
When this profile's IRS filing data changed on Grantable
- IRS filings on file for fiscal years 2020–2024
Explore Open Grants
Browse active grant opportunities in Additional Ventures Foundation's focus areas in our free grants database
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Cite this profile
Grantable. (2026). Additional Ventures Foundation funder profile. GrantGraph. Retrieved October 10, 2026, from https://grantable.co/funders/additional-ventures-foundation-morg_73a3645a323b4a31bee3232cf0675741
BibTeX
@misc{grantable_814429034_2026,
author = {{Grantable}},
title = {{Additional Ventures Foundation funder profile}},
howpublished = {GrantGraph},
year = {2026},
url = {https://grantable.co/funders/additional-ventures-foundation-morg_73a3645a323b4a31bee3232cf0675741},
note = {Accessed 2026-10-10. Data licensed CC BY 4.0}
}The figures on this page are open data under CC BY 4.0: reuse them with credit to Grantable and a link. Download the data.
Figures come from Additional Ventures Foundation's IRS filings (methodology). AI-written summaries, news items and logos are not covered by the open licence. Spot an error? Email hello@grantable.co.
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