Measuring students’ conceptual understandings has become increasingly important to faculty involved in evaluating and improving departmental programs. We developed the Molecular Biology Capstone Assessment (MBCA) to gauge comprehension of fundamental concepts in molecular and cell biology and the ability to apply these concepts in novel scenarios. Targeted at graduating students, the MBCA consists of 18 multiple-true-false (T/F) questions. Each question consists of a narrative stem followed by four T/F statements, which allows a more detailed assessment of student understanding than the traditional multiple-choice format. This talk will discuss the test development process as well as results from administration to more than 500 upper-division biology students. By pinpointing areas of conceptual difficulty, the MBCA can provide faculty with guidance for improving undergraduate biology programs.