To become a certified case manager, you are required to first have a RN degree as well as pass the NCLEX exam to begin practicing as a registered nurse. After becoming an RN, you can choose to go on to obtain your Master's degree in Nursing within a particular nursing specialty. After obtaining your degree, you will receive on-the-job training that can help you to prepare for becoming a certified case manager. When you are ready, you can sit for the CMM exam.