You Might Think Age 65 Is the Right Time to Claim Social Security. Here's Why It Isn't
Seniors who are eligible for Social Security get a range of choices when it comes to filing for benefits. In fact, once you turn 62, you can claim benefits at any time. There's technically no "final age" to sign up for Social Security, though there's no financial benefit to delaying a filing beyond the age of 70.
You may, however, be inclined to sign up for Social Security at age 65 since that's when Medicare eligibility first begins. To be clear, you don't necessarily have to enroll in Medicare at age 65. In some cases, waiting to enroll could make sense (though in some cases, waiting too long could also mean facing lifelong surcharges on Medicare premiums). Generally speaking, though, age 65 is a popular one at which to sign up for Medicare, so at that point, you may be eager to file for Social Security as well.
Source Fool.com