Turning 81 often brings a new stage of retirement. Many people at that age have been collecting Social Security for well over a decade, and their monthly benefit has likely increased several times through annual cost-of-living adjustments (COLAs). But even though government data provides an average benefit amount, no two retirees receive exactly the same check. That being said, here is what every retiree needs to know about what impacts their benefit and how to identify ways you can improve your financial outlook in retirement.