WASHINGTON — A “large proportion” of U.S. workers are unlikely to save enough through their 401(k) or other defined contribution plans to last them through retirement, a government report released Tuesday said.

The study by the Government Accountability Office said that the defined contribution-based system, which has largely replaced the more traditional pension plan, faces and presents “major challenges” for workers.

“While some workers save significant amounts toward their retirement in [defined contribution] plans, a large proportion of workers will likely not save enough in [defined contribution] plans for a secure retirement,” the study said.

The GAO found the trouble with contribution-based plans was particularly acute for low-wage workers. The preferential tax treatment of contributions is unlikely to entice low-wage earners, since these workers already face low marginal tax rates. Additionally, making a contribution out of their take-home pay may not be possible, the study said.

“Many of these workers face competing income demands for basic necessities that may make contributions to their retirement plans difficult,” GAO said in the study.

The report, prepared at the behest of U.S. House Democrats, provoked concern on Capitol Hill.

“Today’s workers will more likely struggle to make ends meet during retirement than previous generations,” Rep. George Miller, D-Calif., said in a statement. “While Social Security faces long-term challenges that must be addressed, this GAO report makes it clear that the real retirement security crisis is the lack of savings in private retirement plan.”

Miller, who chairs the House Education and Labor Committee, noted that GAO projected that 37% of workers born in 1990 and just now entering the workforce would reach retirement age with no savings in a 401(k) or similar account.

Rep. Rob Andrews, D-N.J., said the report shows the “need for action is imperative.”

“Today’s GAO report is a clear indication that a large portion of Americans are heading toward retirement insecurity,” Andrews, who chairs the subcommittee with oversight over pensions issues, said in a statement.

The GAO study suggested policy-makers could take steps to boost the projected savings in defined contribution plans. These ideas include making workers instantly eligible to participate in a 401(k) or similar plan when they enter the workforce, as well as automatically rolling over workers’ retirement savings into a new plan when they leave a job.