There is no way to say with certainty who America’s top living donors are today. Many philanthropic gifts are made quietly, even anonymously, and are never widely known.

Givers who make lots of moderate-size contributions also tend to be less visible—even though they may give away larger total sums than persons who get noticed for one or two huge donations.

So the 149 names that follow should not be considered the final, definitive universe of America’s top donors. However, the lion’s share of our nation’s most generous and influential living practitioners of philanthropy are listed here.

These individuals were compiled from several sources. We started with the Philanthropy 50 list of biggest annual donors, cumulated all of the gifts reported there from 2000-2014, and then identified those persons who gave at least $175 million over that period. To these, we added top givers over that same period from the “Million Dollar List” published by Indiana University. Then we included all of the American signers of the Giving Pledge who were not already showing up on those top-giver lists. Recall that Giving Pledge signers are billionaires who have promised to donate at least half of their fortune to charity; while some are already well on their way to meeting their promise, others will do most of their giving in the future—but they will all be heard from. Finally, we added two smaller groups of donors who have earned plaudits for the perspicacity of their charitable work: Recipients, who are still living, of the William E. Simon Prize for Philanthropic Leadership, and selected contemporary donors identified by the Bridgespan Group as “Remarkable Givers.”

• Bill & Karen Ackman
• Miriam Adelson
• Philip & Nancy Anschutz
• John & Laura Arnold
• Marc & Lynne Benioff
• Sara Blakely
• Arthur Blank
• Michael Bloomberg
• Geoff Boisi
• David & Suzanne Booth
• Donald Bren
• Sergey Brin
• Edythe Broad
• Charles Bronfman
• Warren Buffett
• Ben Carson
• Steve & Jean Case
• Raymond Chambers
• Steve & Alexandra Cohen
• Claudia & William Coleman
• Lee & Toby Cooperman
• Joe Craft
• Joyce & Bill Cummings
• Ray & Barbara Dalio
• Robert Day
• John DeJoria
• Michael & Susan Dell
• Desh Deshpande
• Richard & Helen DeVos
• Barry Diller & Diane von Fürstenberg
• John & Ann Doerr
• David & Dana Dornsife
• Stanley Druckenmiller
• Glenn & Eva Dubin
• David & Cheryl Duffield
• Larry Ellison
• Charles Feeney
• Doris Fisher
• Phillip & Patricia Frost
• Ira & Mary Lou Fulton
• Bill & Melinda Gates
• David Geffen
• Dan & Jennifer Gilbert
• Jeff & Mei Greene
• Ken Griffin
• Gordon Gund
• Harold Hamm
• Frank Hanna
• Reed Hastings & Patty Quillin
• Roger Hertog
• Lyda Hill
• Amos & Barbara Hostetter
• Karen & Jon Huntsman
• Pitt & Barbara Hyde
• Irwin & Joan Jacobs
• Charles Johnson
• Paul Tudor Jones
• George Kaiser
• Vinod & Neeru Khosla
• Sidney Kimmel
• Richard & Nancy Kinder
• Beth & Seth Klarman
• Phil & Penelope Knight
• Charles Koch
• Jan Koum
• Elaine & Ken Langone
• Liz & Eric Lefkofsky
• Marguerite Lenfest
• George Lucas & Mellody Hobson
• Ann Lurie
• Peter Lynch
• Duncan & Nancy MacMillan
• Alfred Mann
• Joe & Rika Mansueto
• Bernie Marcus
• Richard & Nancy Marriott
• Craig & Susan McCaw
• Red McCombs
• Robert Meyerhoff
• Michael & Lori Milken
• Tom Monaghan
• Gordon & Betty Moore
• John & Tashia Morgridge
• Dustin Moskovitz & Cari Tuna
• Charles Munger
• Elon Musk
• Jonathan Nelson
• Pierre Omidyar & Pamela Kerr
• Natalie & Paul Orfalea
• Bernard & Barbro Osher
• Larry Page
• Sean Parker
• Bob & Renee Parsons
• John Paulson
• Ron Perelman
• Jorge & Darlene Perez
• Emily Pulitzer
• Ernest & Evelyn Rady
• Jan & Trevor Rees-Jones
• Julian Robertson
• David Robinson
• Edward & Deedie Rose
• Robert Rosenkranz
• Stephen Ross
• David Rubenstein
• John & Ginger Sall
• Henry & Susan Samueli
• Sheryl Sandberg
• Herbert Sandler
• Denny Sanford
• Vicki & Roger Sant
• Lynn Schusterman
• Stephen Schwarzman
• Walter Scott
• Tom & Cindy Secunda
• Tom & Stacey Siebel
• Craig Silverstein & Mary Obelnicki
• Jim & Marilyn Simons
• Paul Singer
• Jeff Skoll
• John & Susan Sobrato
• Michelle & Patrick Soon-Shiong
• George Soros
• Ted Stanley
• Mark & Mary Stevens
• Tom Steyer & Kat Taylor
• Jon Stryker
• Tad Taube
• Ted Turner
• Walton family
• David Weekley
• Sandy & Joan Weill
• Shelby White
• Oprah Winfrey
• Nicholas & Jill Woodman
• Charles & Merryl Zegar
• Mark Zuckerberg & Priscilla Chan
• Mortimer Zuckerman

Editor’s Note: This list was published in “The Almanac of American Philanthropy” in January 2016.