The decision of AmeriCorps last month to stop enrolling new volunteers because there is not enough money to pay for their education benefits has prompted two investigations.

The inspector general for the Corporation for National and Community Service, AmeriCorps's parent agency, is looking into what led the agency to freeze enrollment. The General Accounting Office, Congress's investigative arm, plans a separate inquiry.

AmeriCorps officials clamped the freeze on new volunteers after determining there was not enough money to pay for the education grants they would earn for their service. The freeze could disrupt some AmeriCorps projects around the country, officials say.

"We take full responsibility for the situation we're in," CNCS spokesman Sandy Scott said.

The inspector general began looking into AmeriCorps spending at the agency's request after senators on the subcommittee that oversees the program's budget raised questions.

"At a time when the public's interest in volunteering is very high, management deficiencies at the corporation must not jeopardize opportunities," Sen. Barbara A. Mikulski (D-Md.), the subcommittee's chairwoman, wrote to CNCS's chief executive, Leslie Lenkowsky, and its inspector general, J. Russell George.

Sen. Christopher S. Bond (R-Mo.) asked GAO to look into the agency's management of the National Service Trust, which doles out educational grants to the mostly college-age volunteers.

Scott would not say whether mismanagement contributed to the freeze, although he said two managers have been reassigned.

He said there was a sudden increase in enrollment of volunteers following the Sept. 11, 2001, attacks and President Bush's call to Americans to volunteer.

The influx -- online applications to AmeriCorps jumped 86 percent in the year after Sept. 11 -- partly exhausted the education trust fund. Scott said AmeriCorps did not ask Congress for new money for the trust fund in the fiscal year that began Oct. 1, 2001.

The agency did request $57 million for the trust fund in the budget year that began this Oct. 1. That money never materialized because Congress did not complete new spending bills, voting instead to continue funding at fiscal 2002 levels.

Scott said the more than $200 million in the trust fund can cover the education benefits for existing volunteers, but not for new ones.

AmeriCorps volunteer Katie Black worked last summer, but the agency says it lacks funds to enroll new volunteers.