The band took to Twitter and said it was a collective decision to part ways, reported Entertainment Weekly.
"As we move into the next chapter of Foster the People we felt it was time to share some news regarding our friend, founding FTP member and bass player Cubbie Fink.
"Over the past several months a collective decision was made that he and the band would go their separate ways and pursue other opportunities," the band said.
"I would like to express my extreme gratitude to our fans for your incredible love and support over the last four years.
Mark Foster and Mark Pontius formed the band in 2009 along with Fink, a friend of Foster. They broke through in 2011 with "Pumped Up Kicks", a crossover hit that peaked at number 3 on the Billboard Hot 100.
The band released two albums together, "Torches" (2011) and "Supermodel" (2014).