Abstract We examine the impact of deregulation and liberalization (D&L) on the efficiency of the Taiwanese life insurance industry from 1981 to 2004. We utilize the data envelopment analysis (DEA) to measure the efficiency performances and the Malmquist index approach to measure changes in efficiency and productivity over time. Both the DEA and Malmquist results show that the old domestic firms have been slightly impacted by the new competitors around 1992–1994 (the end of foreign and new local entry period and the beginning of post-D&L period). More important, our results show that the D&L does not have major adverse impact on the technical, cost, and revenue efficiency performances of existing domestic firms in the long run. The dominance of existing domestic firms has declined but persists throughout the sample period. In addition, our results show that it is relatively easy for new firms to become technically efficient in just few years after entering the market, but it is more difficult for them to become efficient in cost and revenue efficiency. We, thus, suggest that a new market entrant should take advantage of the existing mechanisms by acquiring an old (existing) firm, rather than establish a new one, if a new entrant wants to become efficient in cost and revenue efficiency in a short time.