Purpose - The purpose of this paper is to discuss whether insurers could have a strong motivation for M&A in the future because they need to survive within the industry under oversaturated market conditions. Recently, Japanese non-life insurance markets, mainly the automobile insurance market, have reached the point of saturation due to the oversaturated domestic automobile market. At that time, the industry has also experienced successive large-scale M&A transactions. Design/methodology/approach - Using a theoretical model developed by Salent et al., the authors discuss whether an insurer's motivation for M&A could be affected by a saturation of the market. The authors also clarifywhether insurance premiumderegulation is a necessary condition formerger incentives. Findings - The authors conclude that, first, necessary requirement for insurers' motivation of consolidations is to loosen the rate regulation; and second, the sufficient condition is saturation of market. Research limitations/implications - This result is intuitive to understand recent circumstances surrounding the Japanese non-life insurance industry. Originality/value - This study is believed to be the first to discuss the relationship between a potential market size and M&A transactions. Keywords Acquisitions and mergers, Insurance