For many single or childless individuals, the question of how to distribute their worldly wealth after they die is wide-open and complicated. A charity? Alma mater? Distant nieces and nephews? A cat?

And who will take care of making sure dying wishes are fulfilled?

This dilemma faces not just the 17 million unmarried Americans over 65 who are retired or putting their ducks in a row for retirement. Charitable foundations and financial advisers report that an increasing number of young people are facing these decisions before they are married or have children. That is especially true for tech entrepreneurs who, for example, come into a large amount of money from stock options or the sale of a start-up business.

"There are definitely more young people coming in than 10 years ago," says Mari Ellen Loijens, chief business, development and brand officer for the Silicon Valley Community Foundation, which granted $367 million in 2013 and is handling the disbursement of a $1.1 billion donation of Facebook stock from Mark Zuckerberg. "There's been a real shift in the dynamic."

Case in point is Jeff Kolesky. The 37-year-old software engineer for San Francisco-based OPower Inc says he values the examples that people such as Zuckerberg and Bill Gates have set with their giving.

"For me, I'm not going to be giving away that kind of wealth, but I take value from donating to charity now and not when I'm dead," Kolesky says.

WHEN TO PLAN

When it comes to charitable planning, financial advisers say it is not about how old you are but how rich. If you have $100,000 or more, you do not want to die without a will or estate plan and leave it to a court-appointed executor to decide what happens to the assets you leave behind, says John Pettee, a trust, tax and estate specialist with Charles Schwab's private client division.

"We say to people: 'If you do nothing, your money will go to the state. Is that what you want?' That's enough to make them want to consider something else," says Andrew Russell, a certified financial planner in San Diego.

You also have to consider your healthcare directives and who should manage your affairs should you become incapacitated in an accident or because of illness. A person needs a line-up of contingency names to put on legal forms, and all of those people need to be aware of your desires for medical intervention.

STAY FLEXIBLE

What generally keeps people - with children or without - from estate planning is that they do not want to face their mortality.

"People don't like to talk about death. If you add on top of that they do not have a child who would be a natural heir, they really don't want to deal with it," says Kevin Ruth, head of private wealth planning at Fidelity.

One route to make the process easier is a donor-advised fund, offered by brokerage firms such as Fidelity, Vanguard and Schwab and charitable foundations. These act like mutual funds designated for charitable giving and allow an individual to make a one-time or ongoing contribution through the institution, alleviating many fees and paperwork requirements.

Donors can designate the funds to be distributed right away or can direct grants later. Amy Danforth, president at Fidelity Charitable, says most donors grant their money within 10 years.

Kolesky chose that option late last year shortly before OPower went public. After watching friends deal with tons of paperwork to create their own charitable giving structure after an IPO, Kolesky opened up a donor-advised fund through the San Francisco Jewish Community Federation.

His rationale? It was a well-known entity, the set-up was easy and he has a lot of flexibility to make grants once he is ready. Plus, he gets a tax benefit, because he can claim his donations when he makes them, not when the money is granted to charities.

"It gives me an opportunity to put money away without thinking immediately about where it will go," Kolesky said. "It will create a nest egg of philanthropic, and, in the future, I can give a more impactful amount of money."

People now give just about anything they can assign a monetary value, from unsecured stock options to art and even bitcoins. That helps young tech workers because they can give away some of what they have today, keeping with the principles of the Giving Pledge made by some of the world's wealthiest people, including Gates and Warren Buffett.

"They don't want to delay until 20 or 50 years down the road," says Schwab's Pettee.

And that goes even if kids come later. "Earlier, it didn't matter how rich you were, you were still worried about family legacy," says Loijens. "Now, megarich or not, your obsession with legacy is not the same."