This study applies the concept of the welfare market to pension systems in order to systematically examine the characteristics of public and private pensions. Focusing particularly on private pensions, including occupational pensions, it explores the interests of relevant actors, the market-oriented elements embedded in institutional design, and the modes of regulation that shape these arrangements. Pension systems operate within a welfare market formed through the interaction of public and private pensions, with occupational pensions occupying a particularly important position at the nexus of old-age income security and financial markets. At the same time, welfare markets are marked by a structural dilemma in which excessive regulation may discourage private provision, while insufficient regulation may impede the achievement of public objectives. These findings underscore the need for pension design that balances market efficiency and public responsibility. Accordingly, the use of the welfare market framework in pension systems should be designed to preserve the primary objective of old-age income security, while incorporating sufficient institutional flexibility to avoid undermining private-sector participation.