This study uses a unique synthesized set of data for community college students transferring to engineering by combining several cohorts of longitudinal data along with transcript-level data, from both the Community College and the University, to measure success rates in engineering. The success rates are calculated by developing Kaplan-Meier survival curves measuring retention in engineering over time by grades received in Calculus and Physics courses at both institutions. For each course, survival curves are compared to determine if statistically significant differences exist between levels of grades received. The levels of course grades at which statistically significant differences in retention rates exist are documented. To validate these findings the actual graduation rates in engineering for the same groups of students are estimated using grades received in Calculus and Physics. Policy recommendations based on these findings, including the best time to transfer for this group of community college students, are incorporated.