We expect to give market participants at least six months notice of any change. Any reduction would be across the board, not just in some parts of the country, he said Thursday.
DeMarco also said he plans to continue making gradual increases in the guarantee fees that Fannie Mae and Freddie Mac charge lenders.
The current 50 basis point g-fee has doubled since Fannie and Freddie were placed in conservatorship in 2008.
Lowering the loan limits is one of the most direct ways to increase private sector participation in the mortgage market and reduce taxpayer exposure, he said at a Zillow/Bipartisan Policy Center conference in Washington.
Members of the House and Senate contend that the FHFA does not have the authority to reduce the loan limits without congressional approval.
But DeMarco maintains his actions are consistent with his responsibilities as a conservator when it comes to gradually shrinking the GSEs dominant presence in the mortgage market.