Murray Energy is the only remaining company making significant contributions to the United Mine Workers of America multiemployer pension plan, which was only 38 percent funded as of July, The Wall Street Journal reported.
Monthly benefit payments are an average $596 for pensioners and $368 for surviving spouses, The Journal reported.
Murray Energy was the country's fourth-largest coal producer in 2018, accounting for 6 percent of total production, according to the Energy Information Administration.
The pension plan will be insolvent by its 2022 plan year if it does not receive public funds from Congress, The Journal reported. The plan supports roughly 28 retirees for each active worker, Lorraine Lewis, of the United Mine Workers of America, told Congress in July.
The plan has roughly $2.4 billion in assets but $6.6 billion in liabilities, according to The Journal. Other coal companies besides Murray Energy have filed for bankruptcy this year, a move that can allow them to dodge pension and medical expenditures in order to keep their doors open.
"Chapter 11 has clearly been used, by the coal industry at least, as a convenient way for people to get out of living up to their obligations," union spokesman Phil Smith said according to The Journal.
An estimated 10 million people participate in the multiemployer pension plans and 120 plans that cover 1.3 million workers may go bankrupt. There are 1,400 plans that will be insolvent in 20 years, according to the Pension Benefit Guaranty Corporation.
The Associated Press and FOX Business' Henry Fernandez contributed to this report.