Pursuant to a congressional request, GAO provided information about the accuracy of premiums paid by pension plans to the Pension Benefit Guaranty Corporation (PBGC). GAO noted that: (1) 13 of the 24 plans it studied made premium calculation errors, with most errors involving the calculation of variable premiums; (2) the errors resulted in the plans underpaying their 1990 premiums by less than one percent, and two plans overpaid PBGC; and (3) PBGC is studying the feasibility of conducting field audits to ensure accurate premium payments.