The Pension Benefit Guaranty Corporation (PBGC)’s Pension Insurance Modeling System (PIMS) model has taken on the Herculean task of modeling in detail and under many scenarios the cash outflows associated with the pension obligations they have assumed. This paper’s comments are focused almost entirely upon PBGC’s termination liabilities, and address four pressing issues: (1) the need to discount the liability stream by current riskless interest rates instead of using corporate bond rates that reflect credit risk, call risk, and other risks, or using some ad hoc prescribed average of past rates; (2) the need to use a term structure of interest rates; (3) the need to employ more useful investment management benchmarks; and (4) how to implement a relevant and rigorous liability benchmark.