When you reach age... You Can...
50

(a) Make your first catch-up contributions to your qualified retirement plans. 

(b) Collect Social Security survivor benefits for disabled survivors.
59 1/2 No penalty- Withdraw money from your qualified retirement plans without incurring a withdrawal penalty.
60 Widows and widowers - Collect Social Security survivor benefits for nondisabled survivors 
62 Early-bird benefits - Collect Social Security benefits if not widowed or disabled. These benefits increase for each month you wait to start collecting, until you turn 70. 
65

(a) Enroll in Medicare in the seven-month window that starts three months before the month of your birthday and lasts through the three months after.

(b) Higher deduction-  Claim a higher standard federal income tax deduction than younger tax payers. 
66 Normal retirement age - If born between 1943 and 1954, collect Social Security benefits if not widowed or disabled without early retirement reductions. Monthly checks increase each month you wait to collect, until age 70. 
70 Time to collect - Collect Social Security benefits if you have not already started. Benefits have reached their maximum potential, so delaying only costs you money. 
70 1/2 Mandatory RMDs - Take the required minimum distributions (RMDs) from your tax-advantaged retirement accounts, such as 401(k)s and traditional IRAs.