To protect workers’ retirement security, the requesters asked GAO to assess: 1) What is known about conflicts of interest affecting private sector defined benefit (DB) plans? 2) What procedures does the Pension Benefit Guaranty Corporation (PBGC) have to identify and recover losses attributable to conflicts? 3) What procedures does Employee Benefits Security Administration (EBSA) have to detect conflicts among service providers and fiduciaries for PBGC-trusteed plans? 4) To what extent do EBSA, PBGC, and the Securities and Exchange Commission (SEC) coordinate their activities to investigate conflicts? GAO interviewed experts, including agency officials, attorneys, financial industry representatives, and academics, and GAO reviewed PBGC documentation and EBSA enforcement materials. GAO analyzed Labor, SEC, PBGC, and private sector data, including data on pensions, pension consultants, and rates of return data, and conducted statistical and econometric analyses.