Defined contribution retirement plans have morphed over the last few years from what was intended as a supplemental savings to an employer-provided pension. Now, outside of Social Security, DC plans are the sole source of income for workers in retirement—a drastic change for millions, and not one that rests easy on their shoulders. Not only do DC plans bring new risks to would-be retirees—and to plan sponsors as well—the old risks haven't gone away, but have actually grown. According to Willis Towers Watson, the risks embodied in the shared responsibility for retirement require both sponsors and employees to stay on top of the situation, lest new regulatory requirements or lack of knowledge or attention bring about problems on either side that could have been avoided with forethought and action. Take a look at the slides above for the nine key DC plan risks, as well as some of the actions that sponsors and participants can take to help mitigate them. READ MORE: Lack of understanding about investment risk threatens retirees, workers Creepy, maybe, but smart data can improve retirement savings rates Retirement risks keep rising, and this is why