[Excerpt] The Pension Benefit Guaranty Corporation (PBGC) was established by the Employee Retirement Income Security Act of 1974 to ensure that participants in defined benefit pension plans receive their pensions if their plans terminate without sufficient assets to pay promised benefits. PBGC administers separate insurance programs to protect participants in single-employer and multiemployer plans. PBGC has published the Pension Insurance Data Book annually since 1996 to present detailed statistics on PBGC program operations and benefit protection. In addition to tabular presentations of current and historical data on PBGC’s single-employer and multiemployer pension insurance programs, this edition features two brief discussions. The first describes how the terminations of the plans of two large steel companies after the end of PBGC’s 2002 fiscal year will impact the size and distribution of claims against PBGC. The second describes the current distribution of PBGC-insured hybrid pension plans. This edition also contains graphs illustrating selected current data and trends in PBGC operations and in the U.S. private pension universe insured by PBGC. The publication date for this edition was advanced by several months. As a consequence, data for several tables (S-18, S-20, S-21, S-22, and M-6) whose source is PBGC’s premium filings are not yet available. This edition contains updated 2001 data for these tables. Once the 2002 data are available, we will revise these tables on PBGC’s Web site: www.pbgc.gov/publications/databook.