This chapter provides context for readers who may be unfamiliar with the purposes and range of credentialing strategies that are used by professions, associations, and organizations. Credentialing programs often emerge from a real or perceived need to identify individuals with certain knowledge, skills and abilities, and may be mandatory, voluntary, or some combination of requirements for individuals. The chapter discusses types of credentials that are commonly used in the workforce—specifically, licensure, certification, registration, assessment-based certificates, micro-credentials, and badges. It also discusses a suggested validation framework for credentialing programs along with an illustration from a licensure examination program. The chapter highlights the similarities and differences that certification shares with licensure. It describes some of the challenges of integrating policy and psychometric practice within credentialing along with some of the unique characteristics of credentialing programs when compared with the larger educational assessment arena.