FCA violations can result in both criminal and civil penalties.
Criminal penalties include fines and jailtime. Typically, when a whistleblower reports a violation, the DOJ investigates the report and decides whether to bring criminal charges against the alleged party.
Whistleblowers may also bring a civil suit on behalf of the government, which may result in fines ranging in the tens of thousands of dollars, plus triple the amount falsely paid to the infringing party.