Social Security rewards those who wait
Social Security has a problem on its hands. Social Security pays its recipients from the payroll taxes it collects on current workers, but retiring Baby Boomers are causing the programs tax revenue to shrink and its expense to grow. Social Security has paid out more in benefits than it's collected in tax revenue since 2010, and since then, it's been making up the difference from its savings.
Congress has long known that it would feel the pinch when our parents began retiring, so for decades, it's been offering incentives to people to delay when they claim their benefits.
These delayed retirement credits increase a recipient's Social Security income by a fixed percentage for every month they wait to claim, up until age 70. If you're born after 1943, the credit is two-thirds of 1% for every month you wait, or 8% per year.
It's not as good of a deal as it used to be
Delayed retirement credits only kick in when you reach full retirement age, or the age at which you're entitled to 100% of your Social Security benefit. That age used to be 65, but it's been increasing since 1938, and currently it's 66 and two months.