Quick Read Two hidden 401(k) mechanics, vesting schedules and the absence of year-end true-up provisions, can eliminate thousands in employer matching contributions: under a three-year cliff schedule, an employee loses $6,000 in accumulated match by leaving at two years and eleven months, while lacking a true-up provision costs high earners up to 25% of annual matching if they max contributions early in the year. Job mobility and aggressive early-year savings require careful attention to vesting milest ...