Marinus and Minna B Koster Foundation logo

Marinus and Minna B Koster Foundation

Private foundation · Grantmaker Potomac Falls, VA EIN: 27-1533411 Website

The Marinus and Minna B Koster Foundation is a private foundation based in Potomac Falls, Virginia. Its stated mission is to provide scholarships and financial assistance to musically talented children and young adults, promote the preservation of Yiddish culture, and assist immigrants to the United States, especially Jewish immigrants.

Marinus and Minna B Koster Foundation at a glance

In short: Marinus and Minna B Koster Foundation gave $225K across 18 grants in 2025 (avg $13K), top state District of Columbia. 12% of 2025 grantees were new. Source: 2025 IRS Form 990-PF.

Annual giving (2025)
$225,000
+9.8% vs 2024
Grants made (2025)
18
-5.3% vs 2024
Average grant
$12,500
+15.9% vs 2024
Median grant
$10,000
Total assets
$7,538,830
+7.8% vs 2024
New grantees (estimate)
12% first-time grantees (2 of 17, 2025; small sample)
Primary geography
District of Columbia (41% of itemized 2025 grant dollars)
Latest 990 filing
Form 990-PF, 2025 View filing

Data from IRS Form 990-PF, 2025; updated October 2026. New grantees are estimated by matching recipient names across years (methodology).

How to apply to Marinus and Minna B Koster Foundation

How to Apply

The foundation’s 2024 filing says it does not restrict giving to preselected organizations. It states that application instructions are available on the foundation’s website and that awards are limited to its stated mission.

Review Cycle
The filing lists March 15 as the application deadline for each fiscal year ending June 30. The March 15, 2026 deadline has passed.
Deadline
The filing lists March 15 as the application deadline for each fiscal year ending June 30.
Contact

Application contact: Pnc Private Foundation Management S
Mailing address: Tower At Pnc Plaza 300 Fifth Ave, Pittsburgh, PA 15222
Phone: (412) 762-2083
Email: robert.trinkle@pnc.com
Website: https://themarinusandminnabkosterfoundation.org

Application details from Grantable's research on the foundation's public materials; confirm on its website before applying.

Who Marinus and Minna B Koster Foundation funds

How this funder distributes its grants

Top Recipients

Top 10 recipients in 2025

Edlavitch Jewish Community Center of DC: $30KEdlavitch Jewish CommunityCenter of DC$30KDC Youth Orchestra Program: $20KDC Youth Orchestra Program$20KStrathmore Hall Foundation: $20K across 2 grantsStrathmore Hall Foundation$20K · 2 grantsPennsylvania Women Work: $18KPennsylvania Women Work$18KSitar Arts Center: $18KSitar Arts Center$18KUniversity of Maryland College Park Foundation: $15KUniversity of Maryland CollegePark Foundation$15KCenter for Traditional Music and Dance: $13KCenter for Traditional Musicand Dance$13KAmerican Youth Philharmonic Orchestras: $12KAmerican Youth PhilharmonicOrchestras$12KAmerican University: $10KAmerican University$10KAvodah the Jewish Service Corps: $10KAvodah the Jewish ServiceCorps$10K

The largest 2025 recipient was Edlavitch Jewish Community Center of DC ($30K). Together the top 10 received $166K.

Grant Size Distribution

95 grants across all recorded years

95<$50K$50–100K$100–250K$250–500K$500K–1M$1–5M$5M+

The most common grant size was under $50K: 95 grants of 95 (100%).

Geographic Focus

Where this funder awards grants

The foundation is based in Potomac Falls, Virginia. In 2025, its grant dollars went to recipients in the District of Columbia (41%), New York (26%), Maryland (16%), Virginia (9%), and Pennsylvania (8%).

Grant Distribution by State

6states

Share of 2025 grant dollars across all 18 itemized grants.

Cities

WashingtonNew YorkPittsburghCollege ParkAnnandaleBethesdaNorth BethesdaArlingtonRockvilleAmherstLong IslandPlymouthSilver SpringStaten Island

Is Marinus and Minna B Koster Foundation open to new grantees?

12%

first-time grantees, 2025

In 2025, 2 of 17 grantees (12%) were first-time recipients. With only 17 grantees, that is a small sample: one grantee more or less moves the share by about 6 points. First grants averaged $20K; repeat grants $12K. How we count

Medians: $20K first-time, $10K repeat.

  • 82% of 2025 grantees were also funded in 2024. Method
  • Giving held roughly steady from 2022 to 2025 (−10%). Method
  • In 2025 it paid out 93% of its IRS minimum distribution (the 5% rule). Foundations have until the end of the next year to meet it. Method

Estimate from itemized grant lists in IRS Form 990-PF filings (2018–2025). 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

$0$100K$200K$300K20 grants2018 21 grants2019 17 grants2020 20 grants2021 21 grants2022 17 grants2023 19 grants2024 18 grants2025

From 2018 to 2025, annual grant giving ranged from $180K (2018) to $250K (2022). In 2025 it made 18 grants totaling $225K.

Grants by year

Grant recipients and amounts by year

RecipientPurposeAmount
Edlavitch Jewish Community Center of DC Washington, DCTheater J'S Yiddish Theater Lab$30,000
DC Youth Orchestra Program Washington, DC2025-2026 Talent Development Program$20,000
Pennsylvania Women Work Pittsburgh, PARefugee & Immigrant Services for Employment$18,000
Sitar Arts Center Washington, DC2025-2026 Instrumental Music Academy$18,000
University of Maryland College Park Foundation College Park, MDNational Orchestral Institute +Festival Scholarships$15,000
Center for Traditional Music and Dance New York, NYYiddish New York$13,000
American Youth Philharmonic Orchestras Annandale, VA2025-2026 Tuition Assistance Program$12,000
American University Washington, DCSummer Study Grants for Music Majors- Koster Fdn$10,000
Avodah the Jewish Service Corps New York, NYEnhancing the Capacity of Immigration Nonprofits$10,000
End Sijs Backlog Coalition Washington, DCNational immigration project-national lawyers guild - immigrant youth program$10,000
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Financial History

Multi-year comparison from IRS filings

Figures from IRS filings, by filing year
Filing yearTotal AssetsRevenueExpensesGrants paidGrantsQualifying DistributionsNet Investment IncomeDistributable Amount
2025$7,538,830$455,138$373,262$225,00018$332,803$415,014$356,333
2024$6,992,775$463,944$329,891$205,00019$301,791$435,844$320,432
2023$6,319,551$212,480$325,598$185,00017$293,050$179,932$293,884
2022$5,824,634$289,287$398,032$250,00021$359,629$250,884$330,245
2021$6,904,538$203,260$343,853$222,50020—$172,330$308,454
2020$5,076,018$223,228$302,988$180,50017—$189,166$289,961
2019$5,154,677$114,143$332,950$206,00021—$72,133$280,629
2018$5,373,484$320,614$254,626$180,00020—$253,858$271,055

Under IRS private-foundation payout rules, Marinus and Minna B Koster Foundation reported a distributable amount of $356K for 2025 — the minimum it must pay out in qualifying distributions.

Research compiled by Grantable AI from public sources. Last updated October 2026.

Mission & Focus Areas

The foundation’s stated mission covers support for musical pursuits, preservation of Yiddish language, theater, and scholarship, and services for immigrants, including housing, language, and job training.

Its 2025 grants included support for music education and performance, Yiddish theater and cultural programming, and immigrant employment and legal services. For example, DC Youth Orchestra Program describes its mission as empowering young people through music and community. Pennsylvania Women Work says it helps women advance their careers and achieve self-sufficiency, while the Center for Traditional Music and Dance says it partners with New York City immigrant communities to sustain performing arts traditions.

Grantmaking

In 2025, the foundation reported 18 grants totaling $225,000. Grants ranged from $5,000 to $30,000, with a median grant of $10,000. Among the largest awards were $30,000 to Edlavitch Jewish Community Center of DC for Theater J’s Yiddish Theater Lab; $20,000 to DC Youth Orchestra Program for its talent development program; $18,000 to Pennsylvania Women Work for refugee and immigrant employment services; and $18,000 to Sitar Arts Center for its instrumental music academy.

Other 2025 grants included $15,000 to University of Maryland College Park Foundation for National Orchestral Institute + Festival scholarships; $13,000 to Center for Traditional Music and Dance for Yiddish New York; $12,000 to American Youth Philharmonic Orchestras for tuition assistance; and $10,000 each to American University for summer study grants for music majors and Avodah the Jewish Service Corps for strengthening immigration nonprofits.

Leadership & Key People

Leadership team and compensation from IRS filings

The 2025 filing lists Rosette M Wills as president, Barbara Freedman as secretary, and Michael T Flynn as treasurer. Sterling E Scroggins and Miriam Isaacs are listed as advisors.

Marinus and Minna B Koster Foundation is led by Rosette M. Wills, President since 2019 (on filings since 2018); all 5 officers listed in 2025 are compensated.

Officers on the 2025 filing

  • Rosette M. Wills

    President

    Secretary → President, 2019

    On filings since 2018

    2 hrs/week

    $10K (2018) → $18K (2025)

  • Barbara Freedman

    Secretary

    Treasurer → Secretary, 2019

    On filings since 2018

    2 hrs/week

    $15K (2019) → $18K (2025)

  • Miriam Isaacs

    Advisor

    On filings since 2018

    1 hr/week

    $2K (2018) → $4K (2025)

  • Sterling E. Scroggins

    Advisor

    On filings since 2018

    1 hr/week

    $2K (2018) → $4K (2025)

  • Michael T. Flynn

    Treasurer

    On filings since 2023

    2 hrs/week

    $18K (2023) → $18K (2025)

Former officers (3)
  • Former: Susan Gilbert (2018–2023) — Former Treasurer
  • Former: David C. Metzler (2018–2019) — Former President
  • Former: Alan I. Siegel (2019) — Former Treasurer

Data from IRS Form 990 filings, 2018–2025. "On filings since" is the earliest filing we hold that lists the person; hours are average hours per week as reported.

Compensation Overview

From 2025 IRS filing

Rosette M Wills — President: $18KRosette M WillsPresident$18KBarbara Freedman — Secretary: $18KBarbara FreedmanSecretary$18KMichael T Flynn — Treasurer: $18KMichael T FlynnTreasurer$18KSterling E Scroggins — Advisor: $4KSterling E ScrogginsAdvisor$4KMiriam Isaacs — Advisor: $4KMiriam IsaacsAdvisor$4K

The highest reported compensation on the 2025 filing was $18K, to Rosette M Wills (President). 5 officers or directors reported compensation on that filing.

Frequently asked questions about Marinus and Minna B Koster Foundation

How much does Marinus and Minna B Koster Foundation give each year?

Marinus and Minna B Koster Foundation gave $225K across 18 grants in 2025, according to its 2025 IRS Form 990-PF. In 2024 it gave $205K across 19 grants.

What is Marinus and Minna B Koster Foundation's typical grant size?

Marinus and Minna B Koster Foundation's median grant in 2025 was $10,000, and its average grant was $12,500, across 18 grants on its 2025 IRS Form 990-PF. Organizations receiving their first grant from Marinus and Minna B Koster Foundation that year got $20K on average.

Where does Marinus and Minna B Koster Foundation give grants?

Marinus and Minna B Koster Foundation's top state is District of Columbia, with 41% of the grant dollars itemized on its 2025 IRS Form 990-PF. The next largest states were New York (26%) and Maryland (16%). The most frequent recipient cities were Washington, DC (6 grants), New York, NY (6 grants) and North Bethesda, MD (2 grants).

Does Marinus and Minna B Koster Foundation give general operating support?

Not in 2025: none of the 18 grants with a stated purpose on Marinus and Minna B Koster Foundation's 2025 IRS Form 990-PF were described as general or operating support.

Who are Marinus and Minna B Koster Foundation's largest grantees?

Marinus and Minna B Koster Foundation's largest 2025 grantees include Edlavitch Jewish Community Center of DC ($30,000), DC Youth Orchestra Program ($20,000) and Strathmore Hall Foundation ($20,000 across 2 grants), according to its 2025 IRS Form 990-PF. Together they received 31% of its itemized 2025 grant dollars.

How large is Marinus and Minna B Koster Foundation?

Marinus and Minna B Koster Foundation reported $7.5M in total assets on its 2025 IRS Form 990-PF. It paid out $333K in qualifying distributions that year, against a required minimum of $356K (roughly 5% of its investment assets). Falling short in one year is not a violation: foundations have until the end of the next year to meet the minimum.

What does Marinus and Minna B Koster Foundation fund?

The foundation’s stated mission covers support for musical pursuits, preservation of Yiddish language, theater, and scholarship, and services for immigrants, including housing, language, and job training. See mission & focus areas ↑

How do I apply for a grant from Marinus and Minna B Koster Foundation?

The foundation’s 2024 filing says it does not restrict giving to preselected organizations. Eligibility and process details are in the grantmaking section of this profile. See how to apply ↑

What is Marinus and Minna B Koster Foundation's EIN?

Marinus and Minna B Koster Foundation's EIN (Employer Identification Number) is 27-1533411. IRS Form 990 filing data is available on this page for 2018–2025.

Data last updated October 2026. Sourced from IRS Form 990-PF filings. Research dossier generated October 2026.

Data update history

(4)

When this profile's IRS filing data changed on Grantable

  1. Added Form 990-PF for fiscal year 2018 (received by the IRS April 6, 2020)
  2. Added Form 990-PF for fiscal year 2019 (received by the IRS April 6, 2020)
  3. Added Form 990-PF for fiscal year 2025 (received by the IRS May 12, 2026)
  4. IRS filings on file for fiscal years 2020–2024

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Cite this profile

Grantable. (2026). Marinus and Minna B Koster Foundation funder profile. GrantGraph. Retrieved October 23, 2026, from https://grantable.co/funders/marinus-and-minna-b-koster-foundation-morg_0f92403ac3124f418579a06fa3deb814

BibTeX
@misc{grantable_271533411_2026,
  author       = {{Grantable}},
  title        = {{Marinus and Minna B Koster Foundation funder profile}},
  howpublished = {GrantGraph},
  year         = {2026},
  url          = {https://grantable.co/funders/marinus-and-minna-b-koster-foundation-morg_0f92403ac3124f418579a06fa3deb814},
  note         = {Accessed 2026-10-23. 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 Marinus and Minna B Koster 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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