Additional Ventures
At a glance
Key takeaways
- If your organisation does academic or clinical research into single ventricle heart disease, or research career development, the foundation's stated themes fit; it funds investigators, so a service-delivery charity is unlikely to match.
- Begin with a letter of intent, since only those selected are invited to submit a full proposal, and note that a letter of intent is due once per annual research award cycle.
- The filing shows a median grant of $220,000 and about 8 in 10 grants between $50,000 and $285,000, so a request in that band is typical rather than a limit, and the stated maximums are up to $600,000 for the Independent Investigator Track and up to $300,000 for the Career Development Track.
- Relationships matter: 90% of grant dollars to organisations in the latest filing went to organisations it had also funded in an earlier filing.
- The exclusions apply only to the Single Ventricle Research Fund, which does not fund device design, prototype development, product optimisation, precommercial testing, registry and biorepository builds, or clinical trials.
Overview
Additional Ventures is a US private foundation based in Palo Alto, CA.
What they fund
Profile derived from the foundation's IRS Form 990-PF filings (TY2024, TY2023, TY2022) and its website, with every statement checked against those sources. Sources read on 7 October 2026.
Priority Areas
Additional Ventures funds academic and clinical investigators pursuing work relevant to single ventricle heart disease. Its flagship research programme supports foundational studies intended to improve outcomes, address organ- and multi-organ complications and clinical sequelae, and close gaps in understanding and treatment. It encourages collaboration within the single ventricle community and uses agile approaches to research funding to help researchers move towards a cure. Its filings also record grants to a children’s hospital, reflecting the clinical and research-institution setting of its giving.
Themes
- Single ventricle research
- Single-ventricle device innovation
- Research career development
Geographic Focus
No geographic focus is stated; the filings show grants mainly in California, Massachusetts, Ohio, New York, Pennsylvania, the United States and Europe.
What They Don't Fund
- Single Ventricle Research Fund (SVRF) only: Applications focused primarily on device design, prototype development, product optimization, or precommercial testing; Registry and biorepository build; clinical trials
How to apply
Applicants submit a letter of intent first; those selected are invited to submit a full proposal.
Deadlines: A letter of intent is due once per annual research award cycle.
Application success factors
- Repeat giving: In its TY2024 filing, 90% of its grant dollars to organisations went to organisations it had also funded in its TY2022 or TY2023 filing.
- Grant size: Across its TY2022, TY2023 and TY2024 filings, half of its 211 grants to organisations were $220,000 or less.
What the foundation says:
- For the Independent Investigator Track, collaborative proposals with multiple lead investigators who make significant contributions are encouraged.
- SVRF proposals should connect insights into disease origins to the complications and sequelae shaping long-term survival and quality of life.
Where grants go
From grants to organisations in the foundation’s filings for tax years 2022–2024.
Grant dollars by state
6 other states: 17%
Outside the US or with no state on the filing: 18%
- The largest single recipient received 9% of grant dollars to organisations.
- In tax year 2024, 90% of grant dollars went to organisations Additional Ventures had funded in earlier filings.
- 10% of grant dollars went directly to organisations outside the US (United Kingdom, Italy, Canada, France).
- <1% of grant dollars went to intermediaries that regrant to other organisations.
Grants
How much do they typically give?
Share of 68 grants in tax year 2024 by size
Median $220k (tax year 2024)
The largest grants to organisations in the foundation’s latest filing:
- J. David Gladstone Institutes · Innovation award$1,200,0002024 tax year
- Renata Medical · Transcatheter fontan shunt development$1,100,0002024 tax year
- Boston Children's Hospital · Force fund$934,3172024 tax year
- Nationwide Children's Hospital · Cures collaborative$594,8722024 tax year
- Carnegie Mellon University · Cures collaborative$493,4522024 tax year
- Washington University in St. Louis · Cures collaborative$381,3832024 tax year
- Stanford University · Cures collaborative$322,0502024 tax year
- Emory University · Cures collaborative$302,9932024 tax year
Grants to organisations listed in the foundation’s Form 990-PF filings. Grants to individuals are not shown.
Officers and directors
- Kirstie Keller — CEO
- Tom Van Loben Sels — Secretary
- Michael Schroepfer — CFO / Director
- Erin Hoffmann — President / Chairman / Director
From the latest Form 990-PF filing
3 years of tax filings
| Year | Total expenses | Grants paid | Assets | Filing document |
|---|---|---|---|---|
| 2022 tax year | $10,587,777 | $11,920,946 | $180,921,457 | Filing for 2022 tax year |
| 2023 tax year | $26,204,199 | $16,550,146 | $206,084,034 | Filing for 2023 tax year |
| 2024 tax year | $19,505,047 | $17,151,264 | $220,336,715 | Filing for 2024 tax year |
Figures from the foundation’s IRS Form 990-PF filings. Assets are at fair market value at year end. The document icon links to each year’s filing on ProPublica Nonprofit Explorer.
Sources
Registers and filings
Other sources
🎯 You've done the research. Now write an application they can't refuse.
Hinchilla combines funder's specific priorities with your organisation's past successful grants and AI analysis of what reviewers want to see.
Data privacy and security by default
Your organisation's past successful grants and experience
AI analysis of what reviewers want to see
A compelling draft application in 10 minutes instead of 10 hours
Spotted something that needs correcting? Let us know
At a glance
Applying to Additional Ventures?
Hinchilla drafts your answers around this funder's priorities, using your organisation's own documents.
No credit card required
Contact
- grants@additionalventures.org
- Palo Alto, CA
- additionalventures.org
Applying to Additional Ventures?
Hinchilla drafts your answers around this funder's priorities, using your organisation's own documents.
No credit card required
Contact
- grants@additionalventures.org
- Palo Alto, CA
- additionalventures.org