The billionaire co-founder of Home Depot says he’s planning to give away nearly his entire fortune.

Bernie Marcus, who already has donated about $2 billion to more than 300 organizations worldwide, declined to say how much he’s worth or how much he expected to give away. But his net worth has dropped by roughly half over the past year, to about $4.5 billion, according to the Bloomberg Billionaires Index.

The 90-year-old told the Atlanta Journal-Constitution, which first reported on the plans, that he hoped most of the gift-giving would occur during his lifetime — “I want to live to be 100 because I want to be in a position to give it away to those things that I really believe in.”

Upon his death, the bulk of his wealth will go to and be distributed by the Marcus Foundation, which supports sustainability measures tied to community food resources. He has also outlined philanthropic plans for medical treatment and research, as well as building a national health-care chain to help veterans suffering from brain injuries and post-traumatic stress, the AJC reported.

“I’ve got all the houses I need. I live very well. My kids are taken care of,” he told the AJC. “Everything I live for now is finding the right things to put my money into and that can give me a rate of return in emotion and doing good things for this world.”

Marcus and his wife, Billi, joined the Giving Pledge — a coalition of the world’s wealthiest people committed to giving away at least half their fortunes — in 2010. This came after the couple donated $250 million to build the Georgia Aquarium and millions more to the Marcus Autism Center in Atlanta.

“To make quarterly profits is one thing but changing just one life is so much better,” he said at the time.

The Giving Pledge was launched by Bill Gates, Melinda Gates and Warren Buffett, and its more than 200 pledgers include Michael Bloomberg, Richard Branson and Elon Musk. Buffett, the chairman and largest shareholder of Berkshire Hathaway, announced Monday he would donate about $3.6 billion worth of shares to five foundations as part of that effort, the Wall Street Journal reported.

Marcus is also a major political donor. He was a top contributor to Donald Trump’s presidential bid and at the time wrote “the fate of the nation” depended on his presidency. Marcus told the AJC that he will be supporting the president’s 2020 campaign but emphasized that his philanthropic giving far outpaces his political contributions.

Marcus and Arthur Blank co-founded Home Depot in 1978 after they’d been fired from the same hardware store, Handy Dan, according to Forbes. They built their two Atlanta stores into the world’s largest home improvement retailer, with more than 2,200 locations in the United States, Canada and Mexico. The $231 billion company, from which Marcus retired in 2002, generates about $108 billion in annual sales.