There is a reason for the differentiation, it "saves" the company money. If we got a straight 5% then the company couldn't sit on their share of the match on contributions over 10%. Currently if you contribute more than 10% you have to wait until 1/30 of the following year to receive your true up. In addition, the company match maxes out at $9000 because their liability is capped at $180k (10% of 180k is the 401 k contribution limit, 18k, they give you .50 on the dollar) one of the many things that need fixing