As community colleges across the country implement large-scale reforms to improve student success, they need timely and actionable metrics to determine if the changes they are making in a given year or term will likely improve student outcomes in the long run. In this brief, the authors examine how well nine measures of students' progress in their first year predict student completion in subsequent years, and thus how suitable these early momentum metrics are as leading indicators of the effectiveness of institutional reforms. Based on analysis of student data from all community colleges in three states, the authors find that early momentum metrics do predict longer term success for students. They also find that a key factor in low completion rates, as well as in equity gaps in completion rates, is that many students do not gain early momentum in their first year. College outcomes would be substantially higher if more students met early momentum metrics. These findings indicate the need for comprehensive reforms to community college organization and practice to help more students gain early momentum on their way to earning a credential.