One of my annuities (TIAA) provides for this by what they call the "graded payment option." They pay based on a 3.5% interest rate, and additional earnings go to buy more annuity, so my payment increases by around 6% per year. I think many variable annuities have the same arrangement. Otherwise, you just have to save some of your payment and build a reserve. If you spend less than you take in, then the longer you live the richer you'll get.