Gross, of Potomac, had pleaded not guilty to the charges against him.
U.S. diplomats expressed dismay but not surprise at the length of the sentence, since prosecutors had sought 20 years. U.S. officials hope the Cuban government will release Gross soon on humanitarian grounds, as it has done with other jailed Americans.
National Security Council spokesman Tommy Vietor criticized the sentence as unfair. Gross has already been in prison for 15 months, most of that time without formal charges lodged.
“Today’s sentencing adds another injustice to Alan Gross’s ordeal. He has already spent too many days in detention and should not spend one more,” Vietor said in a statement urging Gross’s “immediate release.”
Gross’s family “is devastated by the verdict and harsh sentence,” said his attorney, Peter Kahn, in a statement. They “have paid an enormous personal price in the long-standing political feud between Cuba and the United States,” he said, adding that he would look into an appeal.
Gross worked for a Bethesda firm, Development Alternatives, which had won a $6 million U.S. government contract to promote democracy in Cuba. Most of Gross’s work involved distributing computer and satellite phone equipment to members of the island’s Jewish community so they could use the Internet, according to his family and U.S officials.
The program was part of a greatly expanded effort begun by the George W. Bush administration to promote democracy in Cuba. But it has been criticized by congressional aides and Cuba analysts as poorly conceived. Gross barely spoke Spanish and traveled frequently to the island on a tourist visa.
Friends said Gross, who had worked around the world on development projects, appeared unaware of the dangers he faced.
His family and the U.S. government have appealed for his release on humanitarian grounds, noting that he has shed 90 pounds and suffered other health problems.
U.S. diplomats have warned Cuba that bilateral relations will not improve as long as Gross is detained. But the case has not stopped the Obama administration from loosening travel restrictions to the island, something supporters say will promote democracy in a more aboveboard fashion, by allowing contact between Americans and Cubans.
Julia Sweig, director for Latin American studies at the Council on Foreign Relations, said Cuba was likely to eventually free Gross to avoid further political tensions at a time when it is focused on its sagging economy.
“There’s no real value to the government of Cuba in keeping him in jail for those 15 years,” she said.