When Spaniard Bernal will no longer be an Under-19 player in 2026, he will have an option to extend for an additional three years, the club said.
Bernal ruptured his anterior cruciate ligament (ACL) during Barca's 2-1 victory at Rayo Vallecano last month, where he was forced off the pitch in the final minutes.
A product of Barcelona's youth academy, Bernal has made three league appearances since his debut for the senior team in their LaLiga opener against Valencia.
"Marc Bernal was, until his unfortunate injury, the huge sensation at the start of the season," Barcelona said in a statement on Monday.
"After he joined manager Hansi Flick for the pre-season, the German coach was convinced that he was ready to move up to the next level."
"The club is convinced that he is a fabulous investment for the future and has reflected this belief with today's new deal."
