As with any question of this sort, the answer is that it always depends.  

The answer always begins with whether you have to have the income immediately or not.   If so, the question is answered!  However, other considerations are your health, marital status, health of your spouse, other savings or retirement income sources, whether you are still working , etc.  Taking benefits prior to full retirement age (age 66 for those born before 1954; higher for those born after 1954) involves reduction of benefits so that is always a red flag.

Prior to 2016, the favored answer was to postpone as long as possible to gain significant increases in benefits.  That often involved having the older of the two spouses “file and suspend” (waiting longer to begin their benefits after full retirement age) and the other spouse then filing for “spousal benefits” at their own full retirement age.  Today, the  ”file and suspend” option is no longer a strategy based on the law passed in 2015.  In fact, it may now often be best not to delay after full retirement age.  Because of the complexity, we use a software package that incorporates the new law and does the calculations that give us the “best” strategy for producing the most income.  

We also use a short health survey that provides a life expectancy and medical cost projection for retirement.  Both these are critical in determining when you should take Social Security.  This gives you the knowledge to make a good decision for yourself.