The Delaware State Capitol

Form 990-PFTax year 2025EIN 85-4039046

Tidemark 10 Foundation

A private foundation in Wilmington, DE. Its return for tax year 2025 lists 16 grants and $1.4 million paid in grants.

Tax year 2025 (period ending Dec 31, 2025), read from the IRS e-file on Nov 11, 2026. Returns reach the IRS 5 to 18 months after the year they describe.

How to apply

Preselected only

The return checks the box saying the foundation gives only to preselected organizations and does not accept unsolicited requests.

Assets and giving by year

6 returns on file
Grants paid by tax year. The latest year is in blue.
  • Tax year 2025

    $1,396,970

    Grants listed
    16
    Assets, end of year
    $9,377,937
  • Tax year 2024

    $8,674

    Grants listed
    2
    Assets, end of year
    $7,782,020
  • Tax year 2023

    $1,000,000

    Grants listed
    1
    Assets, end of year
    $1,509,192
  • Tax year 2022

    $40,500

    Grants listed
    2
    Assets, end of year
    $2,460,561
  • Tax year 2021

    $0

    Grants listed
    0
    Assets, end of year
    $2,525,508
  • Tax year 2020

    $0

    Grants listed
    0
    Assets, end of year
    $1,040,641

Grants paid in 2025

16 grants, largest first

As listed on the return.

  1. Stanford UniversityStanford, CA

    For the center for ocean solutions

    $1,000,000
  2. Fidelity Investments Charitable Gift FundBoston, MA

    General & unrestricted

    $300,000
  3. Nature ConservancyArlington, VA

    California Oceans Program

    $20,000
  4. Carnegie Endowment for International PeaceWashington, DC

    General & Unrestricted

    $10,000
  5. Kqed IncSan Francisco, CA

    General & Unrestricted

    $10,000
  6. Natural Resources Defense Council IncNew York, NY

    General & Unrestricted

    $10,000
  7. PBS FoundationArlington, VA

    General & Unrestricted

    $10,000
  8. Refed IncChicago, IL

    General & Unrestricted

    $10,000
  9. Sustainable SurfManhattan BCH, CA

    General & Unrestricted

    $5,720
  10. Los Angeles Fire Department FoundationLos Angeles, CA

    LA Wildfire Relief

    $5,000
  11. World Central Kitchen IncorporatedWashington, DC

    LA Wildfire Relief

    $5,000
  12. American National Red CrossBoone, IA

    LA Wildfire Relief

    $4,500
  13. LifemovesSanta Clara, CA

    General & Unrestricted

    $2,500
  14. La Cocina IncSan Francisco, CA

    General & Unrestricted

    $2,250
  15. President and Fellows of Harvard CollegeBoston, MA

    General & Unrestricted

    $1,000
  16. Trustees of Princeton UniversityPrinceton, NJ

    General & Unrestricted

    $1,000

Where the money goes

By cause: grants to organizations we matched to the IRS list of exempt organizations, by their category.

  1. Education1 grant $1,000,00094% of the total
  2. Arts and culture2 grants $20,0002% of the total
  3. Environment2 grants $15,7201% of the total
  4. International aid2 grants $15,0001% of the total
  5. Food and agriculture1 grant $10,000<1% of the total
  6. Disaster relief and public safety1 grant $5,000<1% of the total
  7. 1 other causes1 grant $2,250<1% of the total

By State

Grants to organizations with a US address, latest year.

  1. California6 grants $1,025,470
  2. Massachusetts2 grants $301,000
  3. Virginia2 grants $30,000
  4. District of Columbia2 grants $15,000
  5. Illinois1 grant $10,000
  6. New York1 grant $10,000
  7. Iowa1 grant $4,500
  8. New Jersey1 grant $1,000

Officers, directors and trustees

2 people as filed

As filed on the return, with average hours per week and pay from the foundation.

  • David Li YuanDir Hours 1Pay $0
  • Grace YuanDir, Pres, Sec, Treas Hours 5Pay $0

The return

More foundations

Similar foundations

Same main cause (education), giving between a quarter and four times this foundation’s where possible, nearby first.

  1. The Dorothy B Davis FoundationWilmington, DE 26 grants Preselected only $1,400,000 giving
  2. Spector Family FoundationWilmington, DE 46 grants Preselected only $1,403,640 giving
  3. The Timothy and Susanne Sullivan Family FoundationWilmington, DE 14 grants Preselected only $1,405,000 giving
  4. Good Samaritan IncWilmington, DE 21 grants Accepts applications $1,388,000 giving
  5. Lorenzini Family FoundationWilmington, DE 6 grants Preselected only $1,406,903 giving