A CSLB fraud team and the San Mateo County District Attorney's Office participated in the July 22 operation, in which officers posed as homeowners inviting bids on work such as painting, landscaping and concrete work.
According to state law, home improvement jobs with a value greater than $500 for labor and materials must be completed by workers with a state contractor's license.
In the sting, those who bid more than $500 for a job were cited and face a misdemeanor charge of contracting without a license. Eight of the 11 suspects cited also face charges of illegal advertising, according to the CSLB.
"Unlawful contractors are a huge part of California's underground economy and fail to follow California contracting laws," CSLB registrar Steve Sands said in a statement.
"Homeowners may end up paying twice as much for a job if the person demands an illegally high down payment before starting a job or abandons the project before it's completed."