Learning for many adult professionals culminates in some form of assessment. Doctors, cosmetologists, private detectives, insurance agents, real estate brokers, plumbers, contractors, electricians, nurses, roofers, dietitians, and many others are trained in a variety of programs from community colleges to graduate programs, and increasingly their education and testing is conducted wholly or in part via e-learning platforms. Online assessment provides educators with the ability to measure learning needs, assess the results of learning activity, and speed learners toward professional credentialing by leveraging the efficient delivery framework of the Internet. In this chapter, we describe several low- to high-stakes online test delivery methods, which, when coupled with e-learning systems, can offer education providers with valuable opportunities for enriching the validity and credibility of their programs. We discuss the relationship of online assessment models in the context of e-learning, as well as distinguish between the types of testing technologies used to deliver them. We conclude by discussing the advantages and disadvantages of offering assessments online and the future of online assessment systems in general.