A cash balance pension plan must pay a certified class of plan participants $18,677,671 in additional plan benefits and prejudgment interest as a result of its failure to use a whipsaw calculation in determining lump-sum distributions of participants who terminated employment before their normal retirement age, the U.S. District Court for the Western District of Wisconsin ruled Aug. 24 (Ruppert v. Alliant Energy Cash Balance Pension Plan, W.D. Wis., No. 3:08-cv-00127-BBC, 8/24/12).