U.S. defined benefit pension plans lost a record $120 billion last month and are now underfunded, according to the actuarial and business consulting firm Milliman Inc.

"We've been issuing this index for eight years and have never seen a monthly asset loss so large," John Ehrhardt, a co-author of the Milliman 100 Pension Funding Index, said on Monday. The index covers 100 of the largest U.S. defined benefit pension plans.

Subscribe Now

Access to authoritative analysis and perspective and our data-driven report series.

14-Day Free Trial

No credit card required. Complete access to articles, breaking news and industry data.