Luis Enrique and Ricardo Martinelli were released slightly ahead of completing their three-year terms because of good behaviour, a spokesperson for the federal Bureau of Prisons said.
Two of former Panamanian president Ricardo Martinelli's sons were released from US prison after serving sentences for corruption and flew back to their country, with Washington banning the family from re-entering the United States, authorities said.
Luis Enrique and Ricardo Martinelli (namesake of his father) were admitted receiving $28 million in bribes linked to disgraced Brazilian construction giant Odebrecht, of which $19 million had passed through US accounts.
They pleaded guilty in December 2021 after being extradited from Guatemala to the United States.
In May last year, they were sentenced to three years behind bars.
They served two and a half years in total, including time already spent in detention in Guatemala and the US before their conviction.
Following their release, the brothers flew to Panama City on a commercial flight, their lawyer Carlos Carrillo told AFP news agency.
Escorted by US agents, they arrived at the Tocumen airport in the Panamanian capital, where they were notified by justice officials of the charges they face and then released.
In Washington, Secretary of State Antony Blinken announced that ex-president Martinelli and his immediate family members were being barred from entry into the United States.
"Accepting bribes for government contracts undermines the integrity of Panama's democratic institutions and fuels perceptions of corruption and impunity," Blinken said in a statement late on Wednesday.
"These designations reaffirm the commitment of the United States to combat corruption, which harms the public interest, hampers countries' economic prosperity, and curtails the ability of governments to respond effectively to the needs of their people," he added.
Odebrecht admitted in 2016 that it and affiliated entities had paid $788 million in bribes in efforts between 2001 and 2016 to win contracts for some 100 projects in Panama and 11 other countries. It agreed to pay US authorities $3.5 billion in penalties.
Martinelli, 70, who governed Panama from 2009 to 2014, seeks to run for his nation's presidency again in 2024 even though he has been summoned to stand trial on money laundering charges.