According to Joseph Tseng’s 1992 model of the professionalization process in reference to conference interpreting in Taiwan, there are four phases, beginning with market disorder and ending with professional autonomy, which is often realized through licensure. In fact, since 2004, the Graduate Institute of Translation and Interpretation Studies (GITIS), Fu Jen Catholic University and the Graduate Institute of Translation and Interpretation (GITI), National Taiwan Normal University, have begun to organize an annual joint professional diploma examination in conference interpreting. Over the years, both Institutes have gradually moved to delink their students’ performance in the joint professional examination and their graduation with a master’s degree. In other words, the joint professional diploma examination is now positioned as an independent accreditation test organized by two of Taiwan’s most prestigious institutes in the field of interpreter and translator training. At the end of 2007 and the beginning of 2008, the Ministry of Education (MOE) held the first English-Chinese Translation/Interpretation Examination. The examination in consecutive interpretation, both short and long, has aroused much debate about and interest in the interpreting profession. This paper believes the said joint professional examination and the MOE examination can be considered accreditation tests, which, according to Tseng’s model, are one of the important milestones in the professionalization of the interpreting sector. This paper therefore attempts to review the progress that Taiwan’s conference interpreting sector has made toward professionalization during the past decades. Efforts are also made to compare and contrast the two examinations in terms of the significance of diplomas/certificates and implications for the professionalization of interpreting in Taiwan. Finally, based on the aforesaid review, the author proposes a few changes to Tseng’s sociological model.