Across from a television set with the obsolete girth of a model bought 20 years ago, beneath the grandchildren’s crayon artwork taped to the wall, to the left of an abandoned hula hoop, Charles F. Feeney sits in an armchair and explains how he will get rid of his last $1.5 billion, give or take, by 2016.

Just as he did with his first $6 billion, it will all be awarded through Atlantic Philanthropies, the group of private foundations he created in 1982 and managed to run anonymously for its first 15 years, even though it was one of the largest sources of grants in the United States, Ireland, South Africa and Vietnam.

Why shut it down? Mr. Feeney, 81, a man with no romantic attachment to wealth or its trappings, said the world had enough urgent problems that required attention now, before they became even more expensive to solve.

“When you’ve got the money, you spend it,” Mr. Feeney said. “When you’ve spent it all, let someone else get going and spend theirs.”