Mbamba will spend the 2026/27 season at Ligue 1 club Lorient, who are paying a loan fee of around €500,000 for the Belgium Under-21 international's services.
The move continues a pattern established over the past two seasons, following an initial loan at Fortuna Düsseldorf and a more productive spell back in his home country with FCV Dender, where he made 35 league appearances as a regular starter, scoring two goals and providing three assists, despite being unable to prevent the club's relegation via the play-offs.
Leverkusen's director of football, Kim Falkenberg, explained the thinking behind extending Mbamba's contract even as he heads out on loan again. "Noah Mbamba has made a very good and more mature impression on us during the current pre-season in Leverkusen.
"The year-long loan to Belgium at FCV Dender already did him good last season.
"Now, in the French top flight, he will come up against top international players who will challenge him even more in competition and support his footballing progress," Falkenberg said.
Mbamba joined Leverkusen from Club Brugge in January 2023 as a highly rated prospect, but has found first-team opportunities hard to come by given the strength of competition in the Bundesliga champions' midfield.
The new deal, running until 2029, underlines Leverkusen's continued belief in the 21-year-old's long-term potential, even as they look to Ligue 1 to provide the regular first-team football he has so far struggled to find in Germany.