WASHINGTON – Congress told the Internal Revenue Service to halt plans to close 68 taxpayer help centers in Maine and 28 other states, concerned that the tax collectors could be making a penny-wise, pound-foolish decision.

In separate spending bills for the tax agency next year, House and Senate lawmakers told the IRS to delay its plans to close the centers until independent auditors study the effect on taxpayers.

The Senate Appropriations Committee approved its version of the bill on Thursday. It asks the Treasury Department’s inspector general for tax administration to study consequences for taxpayers and their voluntary cooperation with the tax agency, as well as IRS estimates of money saved.

“The committee is highly skeptical of the projected savings from closing these walk-in centers,” the panel said in an accompanying report.

A House bill that was passed last month also called for a study of the closures’ impact on taxpayers.

An IRS spokesman said it would be premature to comment on the bills before a final version of the appropriation legislation emerges from the process.

IRS Commissioner Mark Everson announced in May the planned closure of 68 help centers this fall in anticipation of cuts to the agency’s budget for customer service.

The agency said the centers are the most expensive type of customer service it offers and that fewer taxpayers use them each year. Many questions can be answered more accurately by routing taxpayers to experts over the telephone, the agency said.