[cgbg]

I am waiting until 70 (66 and about to retire now) because:
—Both my parents are still alive (excellent genes)
—I am in excellent health and good shape
—I make a lot more than my wife so I want to maximize her benefits, particularly if I die first
—I can afford to do it and still cover expenses.

Your mileage may vary..

[damper99]

I am waiting until 70 (66 and about to retire now) because: ... —I make a lot more than my wife so I want to maximize her benefits, particularly if I die first...

Your wife, upon your death, will draw what you would have drawn at full retirement age, not what you would draw at age 70. SS stops increasing the survivor benefit after what it would be at your full retirement age, even though your payment did increase up to age 70.

For example if your full benefit at full retirement (e.g., 66) is $2500, but by deferring to age 70 it rises to $3300, she would only get the $2500 not the $3300 upon your death.

Also, if your wife claims her spousal or regular benefit before her full retirement age that percentage reduction is also applied to her survivor benefit.