mine is 66 and 4 months also. From what I understand it goes up around 3% for every year you work past your retirement age. If I retire at 65 I only draw 1800 dollars. If I wait till 66 and 4 months it's 2100 dollars a month. If I work till 70 its 2400 a month But that's the way my statement shows I get every year around my birthday in october.
Using the examples you give, doing the math, you will break even at 85 years of age, all things being equal and assuming you are working until you retire be it either 65 or 70.
I don't know what other factors come into play that may skew the way I am assuming it works out.
Retire at 65. At 85 years of age you will have collected 240 months @ 1800.00 for a total of 432,000.
Retire at 70. At 85 years of age you will have collected 180 months @ 2400.00 for a total of 432,000.
I guess there are two questions.
1st, what to you expect your life expectancy to be? Depending on when you start drawing and how long you live, you will come out ahead or .gov will. Basically, if you are going to expire prior to 85, it is better (larger total) to collect starting at 65.
2nd, can you make use of the extra 600.00 per month when you are in your later years? Sure, you can defer collecting so you can get a larger monthly payment but depending on your health, you may not be able to spend it doing the things you want to do at 80 years old vs things you may want to do when you are 65-70.
I may be totally wrong in my thinking and if I am, please correct me. I still have a few years to go before i have to decide but I keep gong back and forth as to when I want to retire.