The nonpartisan Congressional Research Service has raised new doubts about a plan by Democrats in the House of Representatives to cut interest rates on student loans, saying there are better ways of saving students money.

The plan to reduce interest rates, initially approved by the House in January as part of the “first 100 hours” of Democratic control, would save students an average of $18 per month, the Congressional Research Service said in a report released on Thursday.

“Applying targeted remedies, such as income-contingent repayment plans and/or loan-forgiveness programs, may be more efficient and less costly to the federal government,” the report said.

The findings corroborate concerns expressed by both lenders and advocates for students. The lenders have warned that interest-rate cuts would force them to increase other costs on borrowers.

“We have heard from a variety of sources” that Sen. Edward M. Kennedy of Massachusetts, the Democrat who is chairman of the education committee, “raised questions over whether the interest-rate reduction was as good an investment in college opportunity as increasing the maximum Pell Grant and, assuming that this is Kennedy’s view, I tend to agree with it,” said John Dean, special counsel to the Consumer Bankers Association.

For their part, the student advocates have agreed with the Congressional Research Service that federal money could be better spent on programs such as Pell Grants.

“I actually agree that the interest-rate cuts are of marginal importance,” said Alan Collinge, founder of Student Loan Justice.Org, an advocacy group for borrowers. “In my view, the interest rates weren’t that high to begin with — it’s the sticker price that is the problem.” Mr. Collinge said Congress could provide students with more-meaningful help through such steps as strengthening laws against predatory lending and improving bankruptcy protections.

The author of the plan to cut interest rates, Rep. George E. Miller of California, a Democrat and chairman of the education committee, nevertheless believes the proposal would save a typical student borrower several thousand dollars over the life of his or her loan, a spokesman for Mr. Miller, Thomas Kiley, said.

“For most student borrowers, thousands of dollars in debt relief would be substantial and much-needed,” Mr. Kiley said. —Paul Basken