WASHINGTON — One of the nation’s largest multiemployer pension funds said that it is out of ideas for ways to save itself from an impending failure.
After the Treasury Department rejected its bailout proposal, which would have substantially cut benefits for some retirees, the Central States Pension Fund has little choice but to turn to a federal insurance program that is supposed to offer a lifeline to troubled pension funds.
But there’s one major problem — that program is expected to run out of money, too.
The Pension Benefit Guaranty Corp., which insures private pensions, is dealing with longstanding financial woes with the fund that protects multiemployer pension plans.
The program, which some experts say wasn’t really intended to be used, was set up more than four decades ago to serve as a backstop for private-sector pension plans. But it has been relied on more than expected by large plans on unsteady financial footing.
The fund’s deterioration could pose a threat to the 10 million people in multiemployer plans who could soon be left without a safety net for their pensions.
Although most of those workers and retirees are in plans that are financially healthy, about 1.5 million people — including the Central States members — are in plans that are projected to run out of cash during the next 20 years.
In the past few weeks, lawmakers, Central States officials, and consumer advocates have called for a legislative solution that would shore up fragile pensions and the struggling insurance fund.
‘‘We need a more comprehensive solution,’’ said Representative Marcy Kaptur, a Democrat from Ohio, who introduced a bill last year that would provide the insurance program with government assistance. ‘‘Millions and millions of Americans are affected by this.’’
Previous efforts to bolster the insurance program have failed, or so far fallen short. For example, a 2014 law that made it possible for multiemployer pension plans to cut benefits for retirees was meant to alleviate the burden on the Pension Benefit Guaranty Corp.
But now that the Treasury Department has rejected the Central States proposal, which was the first test under the law, the insurance agency is back where it started.
With roughly $2 billion in assets, the fund for multiemployer plans does not have enough money to pay benefits for the plans that are expected to become insolvent over the next decade.
The Central States fund alone, which pays about $2.8 billion in benefits each year and is the largest multiemployer plan in financial trouble, would overwhelm the multiemployer insurance program if it went under.
The Pension Benefit Guaranty Corp., which insures private pensions, was created as part of the 1974 Employee Retirement Income Security Act to provide another level of security for the millions of Americans counting on pensions in retirement.