Social Security Questions? Ask a Social Security Expert
Hi from Just Answer. I'm PDtax, and can assist.
There is a may 1, 2016 effective date for certain strategies, such as file and suspend if you were married and looking to set up a spousal benefit for your spouse.
Since you didn't mention a spouse, I assume this is for your benefit on your work record.
There are filing options to be considered before May 1, 2016, but most apply to married claimants. There is no provision I know of that would reduce your benefit at age 70.
You do not need to file any extension to maintain your age 70 benefit as you intend to claim.
Thanks for asking at Just Answer. Positive feedback is appreciated. I'm PDtax.