Founders & Staff

  • Founders’ Story

    Sammy Politziner and Scott Thomas met while freshmen at the University of Michigan. Their friendship has been built on a shared thirst for adventure travel, avid fandom of Michigan sports, and, as it has turned out, a passion for social justice. After both serving as educators through Teach for America, they managed to navigate graduate school and careers in finance while preserving a tradition of annual pilgrimages back to Ann Arbor.

    On one such trip, in 2008, they realized they both yearned to be a “part of the solution” to the challenges they saw in their adoptive home of New York City.  After two years of tackling pilot projects on nights and weekends, this instinct eventually evolved into Arbor Brothers – a nonprofit focused on empowering low-income families to secure a path out of poverty by providing crucial supports at critical moments to high-potential nonprofits.

  • Sammy Politziner


    Sammy graduated from the University of Michigan and moved to New York City, where he taught second grade in the South Bronx with Teach for America and founded a small academic summer camp for his students.  After a stint of world traveling, Sammy moved north for a master’s degree from the Harvard Graduate School of Education and then down south to teach at a KIPP school in North Carolina.  Sammy returned to New York for a job in investment banking at Kildare Capital, a boutique firm, where he spent five years providing sell-side M&A and capital formation advice.

    In addition to co-leading Arbor Brothers, Sammy serves on the board of directors of Exponent Philanthropy, the nation’s largest association of funders, and All Our Kin, an Arbor Brothers alumni grantee. When not working, Sammy often dreams of starting a family band, running marathons in faraway lands and Michigan football winning the national championship (or at least beating Ohio State, for goodness’ sake).

  • Scott Thomas


    Scott earned an engineering degree from the University of Michigan, which he promptly misplaced and came to work as a middle school mathematics instructor through Teach for America in NYC’s Washington Heights neighborhood.  After another left turn to collect an MBA from NYU, Scott joined Lehman Brothers and later Neuberger Berman, where he helped manage investments in infrastructure and alternative energy companies.  Feeling the call to unite the social justice and business aspects of his career, he co-founded Arbor Brothers with Sammy in 2010 and continues to co-lead it today.

    Scott is grateful to serve on the board of GirlTrek, an Arbor Brothers grantee, and Summer Search, a national youth development organization.  He has had the opportunity to guest lecture at Harvard, Columbia & NYU and is a member of the Leap Ambassadors Community.  When he’s not in the office he can be found alongside every other Brooklyn dad, chasing his family and dog through Prospect Park.  He loves traveling to off-the-beaten path locales, though he still grimaces when recalling the time his “friends” hoodwinked him into packing for a canoeing voyage before a trek into the Tunisian desert.

  • Rebecca Cullen


    Prior to joining Arbor Brothers in 2020, Rebecca served as the President at College Advising Corps, a national college access organization, where she oversaw a $45M budget and led 50+ staff members to increase opportunity annually for 200,000+ low-income, first-generation, underrepresented students. Before College Advising Corps, Rebecca fostered her passion for social justice at the Jack Kent Cooke Foundation where she spent more than a decade developing scholarship programs to advance the education of high-achieving, low-income students across the country. Earlier in her career, Rebecca managed an after-school learning center at Kaplan, worked in independent school admissions, coached refugees to find employment, and taught English in Russia.

    Rebecca earned her BA in history at Georgetown University. She enjoys travel, yoga, walking, tennis, and singing.

  • Indira Martinez Pamias

    Senior Associate

    After graduating from the University of Georgia with an International Affairs degree, Indira spent three years living and working in communities abroad, first assisting with research on refugee populations in Ecuador and then serving in the Peace Corps as a Youth Development volunteer in Guatemala. She then returned to the United States to obtain a Master’s Degree in Public Administration and a Master’s Degree in Social Work from Columbia University. While earning her degrees, Indira developed her expertise in monitoring and evaluation while working with a variety of nonprofits in the city on issues ranging from girls’ education to global eye health.

    Indira joined the Arbor Brothers team as a Senior Associate in 2020 and lives in West Harlem, where she serves as an elected County Committee member for her community.

  • Courtney Tran

    Senior Associate

    Courtney’s interest in community development began in California, where she served on the Oakland Public Library’s Youth Leadership Council, volunteered with the Berkeley Anti-Trafficking Coalition and supported research into social determinants of health in America. After graduating from UC Berkeley, she moved to New York City to complete a fellowship at Human Rights Watch, where she investigated attacks on medical facilities in conflict zones. She then completed an international development fellowship with the International Innovation Corps and the Self-Employed Women’s Association in India before returning to New York to earn a Master’s in International Affairs at Columbia University.

    Courtney joined Arbor Brothers as a Senior Associate in 2020. In addition to her human rights and development background, she has nine years of private teaching and tutoring experience.


Board of Directors

This core group of supporters bears fiduciary responsibility for the organization and ultimately selects the constituents of each grant portfolio.

  • Sean Sauler

    Arbor Brothers Board Chair | Co-CIO / Deputy CEO and Portfolio Manager at Redwood Capital Management

  • Michael Braner

    Managing Partner at 325 Capital

  • Ingrid Dyott

    Managing Director, Senior Portfolio Manager at Neuberger Berman

  • Greg Geiling

    Managing Director, Co-COO at Bayview Asset Management, LLC

  • Ken Glassman

    CEO & Chief Investment Officer of RWN Management, LLC

  • Geoff Goldstein

    Managing Director at JLL Capital Markets

  • Erica Hamilton

    Chief of Staff & EVP at the Institute for Nonprofit Practice

  • Emily Keenan

    Teach for America (retired)

  • Scott Lebovitz

    Partner, Global Co-head of Infrastructure Investing & Head of Energy Investing at Goldman Sachs

  • Sammy Politziner

    Co-founder of Arbor Brothers

  • Chris Rush

    Senior Advisor for Innovation & Director of Educational Technology, U.S. Department of Education; Co-Founder and Chief Program Officer at New Classrooms

  • David Sambur

    Co-Lead Partner, Private Equity at Apollo Global Management

  • Francisco Tezen

    President & CEO at A Better Chance

  • Scott Thomas

    Co-founder of Arbor Brothers


Board of Advisors

From the beginning, the generously shared insights of these experienced social entrepreneurs have played an instrumental role in Arbor Brothers’ development.

  • Jamar Adams

    Founder and Managing Principal at Essence Development, All-Big Ten Safety at Michigan

  • Cathy Bacich

    Arbor Brothers Board Member (2012-2019)

  • Nick Ehrmann

    Account Executive at SalesForce; Founder of Blue Engine

  • Michael Ellis

    Managing Director & COO at Inherent Group, Founding Board Member of Arbor Brothers

  • Peter Frey

    Private Investor; Partner at TRG Management (retired)

  • Matt Klein

    Executive Director at the Center for Economic Opportunity

  • Rich Leimsider

    Executive Director of the Safe Passage Project

  • Nitzan Pelman

    CEO and Founder of Climb Hire

  • Jessica Sager

    Co-Founder and Executive Director at All Our Kin



We are extraordinarily grateful to the people who power our work: our donors.

This generous group of families and foundations has refused to accept that life circumstances should dictate access to opportunity. Since 2009 their investments in Arbor Brothers have helped build and sustain organizations working every day to transform the lives of young people in our community.

Contribute to the Solution

Arbor Brothers finds, funds, and deeply supports the most promising second-stage nonprofits in the tri-state area.