Carlos Holguin, Colombia's justice minister, said the men will face trial in US courts for charges including cocaine smuggling.
Holguin said: "Most of the top bosses are there. In some cases they were still committing crimes and reorganising criminal structures."
Those extradited include Salvatore Mancuso, the most senior leader, Diego Murillo, known as Don Berna, and Rodrigo Tovar, who went by the nom de guerre Jorge 40.
They were flown from Rionegro airport, 400km northeast of Bogota, Colombia's capital.
Holguin said that the extraditions did not mean the end of the peace process with the paramilitaries
Set up by landowners to fight against the left-wing Revolutionary Armed Forces of Colombia group, the right-wing paramilitaries soon controlled large swathes of Colombia.
They massacred and drove peasants from their land in one of the bloodiest chapters in Colombia's four-decade-old conflict.
Under the 2003 pact, the paramilitaries were supposed to confess to their crimes, surrender their ill-gotten riches and promise to stop committing crimes in exchange for reduced jail terms.
Tuesday's move comes after last week's extradition to the US of Carlos Mario Jimenez, known as Macaco, one of the country's most wanted paramilitary leaders.
The Colombian government accused him of continuing to run his drug gangs from behind bars.