American and GOL have been frequent flyer partners since August 2009, when members of AAdvantage and GOL's Smiles program could start earning miles when traveling on each other's flights.
In November, Smiles members began redeeming their miles for flights on American.
And this month, with AAdvantage members' ability to use their miles for GOL flights, the relationship becomes fully reciprocal.
Among U.S. carriers, American has the most service to Brazil, with flights to Sao Paulo, Rio de Janeiro, Belo Horizonte, Recife, and Salvador from Miami, New York, and Dallas/Fort Worth.
GOL operates 800 daily flights to 50 destinations in Brazil and ten cities in South America and the Caribbean.
Later this year, American and GOL will begin codeshare flights, making it that much easier for U.S.-originating travelers to fly to destinations within Brazil, and for Brazil-originating travelers to reach interior U.S. points.