Democrats have criticized the Christie administration's choice of a firm that bid $2 million more than the lowest bid.
The "Stronger than the Storm" campaign starred Christie and his family. The losing proposal wouldn't have featured them.
The Department of Housing and Urban Development's inspector general says the audit's examining whether the campaign followed federal requirements, not the way the contract was awarded.
Democratic U.S. Rep. Frank Pallone Jr. says the review was undertaken at his request and includes "the bidding process." A Pallone spokesman said Thursday he's glad the agency is complying with his request.
A Christie spokesman has said the federal government approved the campaign.