The financial regulatory structure in the U.S. is both too complex, and too fragmented, according to a report published on Monday by the U.S. Government Accountability Office (GAO).

Although the sector has undergone a great deal of regulatory reform in response to the financial crisis, these efforts largely left the regulatory structure itself unchanged, the GAO report notes.

As a result, firms still have to answer to multiple regulators with overlapping jurisdictions, and this can pose a challenge to effective oversight, the report says.

“Fragmentation and overlap have created inefficiencies in regulatory processes, inconsistencies in how regulators oversee similar types of institutions, and differences in the levels of protection afforded to consumers,” the report says, and this impacts the banking, securities, and insurance sectors.

For example, the regulation of the swap and security-based swap markets by separate agencies “creates potential market inefficiencies because of differences in certain of the agencies’ rules for each product,” the report says.

The report calls on the U.S. Congress to consider reforms to address these concerns, and to ensure that the authorities are better able to deal with possible systemic risks.

Indeed, the one structural reform that was brought about in the wake of the financial crisis was the creation of the Financial Stability Oversight Council (FSOC) and the Office of Financial Research (OFR). However, the GAO says that “collaborative efforts [between these new authorities and existing regulators] have not been sufficient, and FSOC’s authorities are limited and unclear.”

Without congressional action, the GAO says that the FSOC “may not have the tools it needs to carry out its mission to comprehensively respond to systemic risks, and it may be difficult to hold the council accountable for doing so.”