It is better to use a higher age rather than a lower one. If you spend you money assuming you are going to die at age 80 and live to age 92 you might be out of money before age 92. My grandfather outlived his money when he lived to 94. He was getting a lot of government assistance for the last years of his life. There was no money to go to his heirs. It was only the contents of his studio assisted living apartment that was left when he passed.