At the age of 16, despite being a U.S. citizen, he signed a contract with the Nationals on July 2, 2016, as an international free agent out of the Dominican Republic.

[5] García advanced quickly in the 2018 season, earning a midseason promotion from the Single-A Hagerstown Suns to the High-A Potomac Nationals, and he was the youngest player and the first ever born in the 2000s selected to the All-Star Futures Game in 2018, playing for Team World against fellow Nationals infield prospect Carter Kieboom and Team USA.

[6] García was the youngest player invited to participate in a major league spring training camp in 2019, with the Nationals.

[8] On August 14, 2020, García's contract was selected to the major leagues and he made his debut that day against the Baltimore Orioles, filling in for the injured Starlin Castro.

[9] Coincidentally, Castro, who he replaced due to injury, was the first MLB player born in the 1990s to hit a home run.

He became the Nationals everyday second baseman, following the trades of infielders Josh Harrison and Trea Turner as well as the suspension and subsequent release of Starlin Castro.