Technically retirement age is 65 (might have moved to 67). But don't worry, Republicans have proposed moving the retirement agree to 75. That'd really cut down on the senators past retirement age and they don't even have to retire!
Having a retirement age of 67 should be seen as a complete failure of our society. Boeing did a study that found if their employees retired at 55, then they collected retirement benefits on average for 25 years - dying at 80 years old.
However, those that retired at 65 only collected retirement benefits for 2 years 18 months - dying at 67. Basically meaning that for every year you work past 55, you're missing out on 2 years of retirement (working an extra year and also taking a year off your life).
A retirement age of 67 is basically the same as having no retirement age at all. It's just a "fuck you, work till you die."
Couldn't this just be an indirect way of saying people with more money live longer? Retiring at 55 means you're pretty well off, retiring at 67 likely means you couldn't afford to retire early. Less money means lower ability to afford healthy food and medical care.