Several months into a credit crunch that has led at least 20 lenders to leave the guaranteed loan program or suspend their lending operations, lawmakers have begun to respond with a sense of urgency, even as they seek to reassure students and parents that a crisis is unlikely and that federal student loans will still be available this fall. In the end, though, there may be little that Congress can do to shore up the federal student-loan system, beyond pressuring other government entities, like the Education and Treasury Departments, to take action. A few members of Congress had voiced concerns that credit-market disruptions could threaten the availability of federal student loans even before the Pennsylvania Higher Education Assistance Agency (Pheaa), largest of the state-based nonprofit loan agencies, announced in February 2008 that it would suspend its federal student-loan operations. But until then, only for-profit lenders had withdrawn completely from the federal program, and most people assumed that organizations of Pheaa's size and could always find money to provide loans. To date, the departures do not seem to be having an effect on student-loan availability, in part because banks have stepped in to fill the gaps left by non-bank lenders. Both Congress and the Education Department believe they will continue to do so. Some lenders aren't so sure. They say subsidy cuts enacted by Congress last year have cut into lenders' profits so deeply that some banks are becoming reluctant to expand their student-lending operations. In light of this, some lenders are urging Congress to roll back the subsidy cuts to make student lending more attractive. But even supporters of that idea acknowledge that Congress is unlikely to do it, given the high cost. Instead, lawmakers and lenders alike are focusing their efforts on the increasingly popular private student-loan market, where the effects of the credit crunch have been the most pronounced. Experts say there is little Congress can do on its own to inject liquidity into the capital markets. But it can play a role by urging the Treasury Department and the Federal Reserve to intervene in the student-loan market, and by pressing the Education Department to prepare for a potential crisis. So far the chairmen of the education committees have focused on the Education Department, urging the secretary to test-drive its "lender of last resort" program and ensure that the federal direct-loan program is prepared to handle an influx of borrowers if more lenders abandon guaranteed loans. Under a "lender of last resort" program, guarantee agencies could lend directly to students who were unable to get loans from a traditional lender. Intervention from the Treasury or Federal Reserve has not yet been sought, perhaps because the lawmakers remain confident that the markets will correct themselves.