I am turning 66 in July of 2018. Can I apply in January 2018 and receive my full retirement age benefits 6 months early in the year i turn 66?
No, you can't. If you'll earn less than $44,880 (or whatever the exempt amount of earnings is set at in 2018) in the months prior to the month you reach age 66, you could start drawing benefits effective with January. However, your benefit rate will be permanently reduced by about 3.33% if you do so.
You may want to run the maximization software available on this website before you make any filing decisions. You may have better filing options available to you.