With the series "Advancement for Low-Wage Workers," Jobs for the Future seeks to elevate discussion of this critical issue within and outside the workforce field. These occasional papers address public policy and on-the-ground practice. "The Next Challenge," the series introduction, argues for placing not just employment, but also advancement at the center of employment and training policy. It defines career advancement as a goal, explores key challenges and opportunities, and highlights strategies to help significantly more low-skill workers move up to better jobs and family-supporting earnings. [Introduction to a series of reports on Advancement for Low-Wage Workers.]