Large U.S. banks have major risk-management flaws that could potentially hurt the broader financial system if not addressed, Federal Reserve Chair Janet Yellen told lawmakers Wednesday.

At a House Financial Services Committee oversight hearing where she was grilled by Republicans on what they view as the Fed’s intrusive role in the economy, Yellen pointed to actions the central bank has taken to stabilize banks and the financial system since the 2008 credit crisis. Without providing details, she also promised measures in the coming year “that will complement the steps we have already taken.”

“Substantial compliance and risk-management issues” are still present in big lenders regulated by the Fed, Yellen said. “Compliance breakdowns in recent years have undermined confidence” in the banks’ ability to manage risks and “could have implications for financial stability, given the firms’ size, complexity and interconnectedness.”

The Fed is working with other U.S. banking agencies to identify regulations that are “outdated, unnecessary or unduly burdensome,” she said.

A rule on the Fed’s emergency lending authority is coming by the end of this month, Yellen told the committee. Those powers, used by the central bank to assist banks during the financial crisis, were restricted by Congress when it passed the Dodd-Frank Act in 2010. The Fed still needs to complete rules detailing how it will implement the changes.

Yellen was less specific in answering a question about when the Fed will finish a rule on banker compensation that it’s working on with other financial regulators. Dodd-Frank required an executive pay regulation to discourage banks from giving incentive pay packages that encourage excessive risk-taking. Regulators were supposed to have finished the rule by 2011.

Yellen told the committee that she would support only a modest increase in the asset level for subjecting banks to tighter oversight. She has said banks just above the $50 billion threshold set by Dodd-Frank face costly demands such as requirements to undergo stress tests and write plans for how they could go through bankruptcy in a failure.

The House panel and the Senate Banking Committee have asked Yellen to appear twice-annually to talk about supervision and regulation because President Barack Obama hasn’t nominated anyone to be vice chairman for supervision, a position created by Dodd-Frank. The person in that job would have to appear twice a year before those committees.

Fed Governor Daniel Tarullo has been the central bank’s point person on regulatory matters without having been nominated to be vice chairman.