[영문]The pension landscape in the U.S. has changed dramatically over the past 25 years. Saving through personal retirement accounts has become the principal form of retirement saving. We document the transition from a defined benefit system to a personal account system and show the effect it has had on wealth at retirement. We summarize results from other research we have done to project the growth of retirement assets over the next three decades. Our projections suggest that the advent of personal account saving will increase wealth at retirement for future retirees across the lifetime earnings spectrum.