If you do choose to contribute the maximum, be aware that your maximum contribution is the sum of your maximum regular elective deferral ($18,000), catch-up if age 50 or older in 2016 ($6,000), and the remainder is employer matching contribution. You should document the breakdown of your contributions. Some trustees ask for that on they're contribution forms, so you'll need to be sure that the totals of each portion do not exceed the portion maximums.
