Abstract Pension administration remains central to the financial security and social welfare of retirees in Nigeria. Despite the introduction of the Contributory Pension Scheme (CPS) in 2004 and subsequent reforms in 2014, retirees continue to experience delayed benefits, financial instability, and declining trust in the pension system. This paper examines two critical challenges undermining effective pension administration in Nigeria: firstly, employers’ non-remittance of mandatory counterpart pension contributions and secondly, corrupt practices among pension administrators. Drawing from empirical and theoretical literature as well as documented pension reforms, the study reveals that persistent non-remittances disrupt pension fund accumulation, deepen pension arrears, and erode pensioners’ welfare. The study also finds that corruption manifests in embezzlement, falsification of records, diversion of funds, and administrative opacity, ultimately weakening governance and accountability within the pension system. The paper concludes that without stringent enforcement mechanisms, transparent administrative structures, and improved regulatory oversight, pension reforms may continue to fall short of guaranteeing retirees’ long-term welfare.