Geithner is testifying just one week after the independent member of the FSOC with insurance expertise, Roy Woodall, was confirmed by the Senate for a six-year term.

The FSOC was established under the Dodd-Frank financial services reform law to ensure that financial problems at large insurers and brokerages as well as banks do not cause another financial crisis.

Geithner is also expected to be asked about the role the Federal Insurance Office, also established under Dodd-Frank, will play in overseeing the insurance industry. The industry and Republican members of the committee want states to remain the primary overseer of insurance companies, with the federal government just playing an advisory role in the absence of a crisis involving insurers.

Large insurers have already asked members of Congress to pressure the FSOC to re-propose the rule by which the FSOC establishes the criteria for designating an insurer as systemically significant.

Insurers are wary of such a designation because it will allow the Federal Reserve Board to oversee them, thereby imposing additional regulation.

Insurers also oppose the designation because it would give federal regulators authority to potentially impose a 3 percent additional-capital charge on designated companies and force them to contribute up front to a fund the FDIC would use to wind down a trouble financial company, whether it be an insurer, bank or securities firm.

No insurance companies have been identified yet as SIFIs, or systemically important financial institutions.

House Republicans are expected to inquire about overlapping regulations and ask what actions the Treasury Department is taking streamline or eliminate existing regulations for the financial services industry, as promised earlier.

Geithner was previously supposed to testify on the first annual FSOC report. The report was issued in July, but Geithner requested a delay because he was busy dealing with solvency issues, many concerning troubled European countries.

In a letter, Republicans write to Geithner, "As concern mounts about the effect that regulatory overkill is having on economic growth and employment, we are writing to request that you provide the committee with a report on what the [FSOC] is doing to identify and eliminate unnecessary or duplicative regulatory burdens."

It adds, "…we have seen no evidence in the year since Dodd-Frank was enacted of any efforts by the administration to 'streamline and simplify' regulations."

Geithner had formerly stated he would take such streamlining steps in an Aug. 2, 2010 speech.