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Julie Halpert, special to CNBC.com

Andrew Aran has accumulated a significant amount of wealth as a registered investment advisor. But when he passes away, his three children—now 26, 22 and 16—will not see a large inheritance.

Aran, 57, and his wife, who live in Wyckoff, New Jersey, plan to gift the bulk of their estate to charity, with only a small portion going to his children.

“We don’t want to negatively impact their work ethic,” Aran said.

A 2014 study from the Boston College Center on Wealth and Philanthropy projects that $36 trillion will be passed down from boomer estates to heirs between 2007 and 2061 (the total wealth transfer broader than estates will reach $59 trillion). But that’s not necessarily going to be the windfall the children of boomers—the Gen X- and Gen Yers—expect.

A 2014 U.S. Trust Wealth and Worth survey found that baby boomers are less likely than any other generation to believe it is important to leave an inheritance to their heirs. While 53 percent of boomers feel it’s important to leave a financial inheritance, that number is 68 percent for those over the age of 69.

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That’s because a heavy percentage of the survey participants were first-generation wealthy and feel their children should earn their own money just like they did, said Chris Heilmann, chief fiduciary executive of U.S. Trust.

The most famous—and richest—proponent of this approach to inheritance is Warren Buffett, who created the Giving Pledge to convince more of the world’s ultrarich to leave a majority of their fortunes to nonprofits rather than family.

Buffett was famously quoted saying, “My family won’t receive huge amounts of my net worth. That doesn’t mean they’ll get nothing. My children have already received some money from me and Susie and will receive more. I still believe in the philosophy … that a very rich person should leave his kids enough to do anything but not enough to do nothing.”

“The thought that it can go to help others makes me sleep a lot better at night.”-Craig Wolfe, CelebriDucks owner, on giving the majority of his estate to nonprofits

As a generation of activists, many boomers are interested in leaving a philanthropic legacy.

Mitchell Kraus, a financial advisor with Capital Intelligence Associates, said many parents of boomers don’t talk about money in terms of what is important to their value system and that the boomer generation has more causes and tries to pass down values and assets in a different way. Aran said that while his children “didn’t shout for joy” when they learned about his decision, he feels strongly about using his financial prosperity to help worthwhile efforts.

Craig Wolfe, 61, who lives in San Rafael, California, has a net worth between $3 million and $4 million—amassed as owner of CelebriDucks, the largest custom collectible rubber duck manufacturer.

He says his daughter is financially comfortable, doesn’t need an inheritance and is supportive of his decision to give most of his money to nonprofits. He didn’t anticipate becoming wealthy and feels an obligation to give back.

“The thought that it can go to help others makes me sleep a lot better at night,” Wolfe said.

Dan Rothblatt, senior vice president of philanthropic services for The Jewish Community Foundation of Los Angeles, who advises boomers, said many find philanthropy adds meaning to their lives, and in ways that often depart from priorities of their children.

The flip side of the giving boom

Not every boomer has the luxury of a dilemma over how to parcel out the wealth of a lifetime, because many don’t live within their means, said Nicole Mayer, a partner at holistic financial planning firm Life Transition Specialists.

Mayer knows of boomers who, instead of paying more for their aging parents’ medical care, are, in fact, banking on a hefty inheritance from their parents to help finance their retirement. For many years, she said, boomers had secure jobs and lived by the mantra, “The bigger, the better,” spending money on large houses, intent on having more than their parents, Mayer said.

Boomers—who grew up in the aftermath of the Cold War, global uncertainty and rising inflation—had an attitude of “Spend it now because it will be more expensive later or we won’t be here later,” said Leon C. LaBrecque, CEO of wealth management firm LJPR.

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Now, even basic expenses, such as health care, will tap into their lifetime accumulation of wealth. To that point, 50 percent of all medical expenses are spent in the last five years of your life. And with life expectancy as high as 85, “you’ve added five of the most expensive years of your life,” LaBrecque said.

Michael H. Baker, a certified financial planner with Vertex Capital Advisors, said boomers’ parents, who lived through the Great Depression, were world-class savers. They also had the advantage of a defined benefit pension plan rather than a 401(k). Baker said leaving an inheritance to children is at the bottom of the list for many of his boomer clients.