Bush suffered a severe knee injury in 2015 at the Edward Jones Dome and filed a lawsuit against the team in 2016.
The Rams were ordered to pay him $4.95 million in compensatory damages and $7.5 million in punitive damages after being found 100 percent liable.
"I'm very happy with the verdict," Bush said Tuesday. "The people spoke and decided very fairly."
While injuries are a common occurrence in the NFL, the running back's injury came as a result of an unsafe surface at the dome. Bush—then a member of the San Francisco 49ers—slipped on a concrete surface after being pushed out of bounds on a punt return.
The team covered the concrete with a slip-resistant surface two weeks later.
Bush had also filed a lawsuit against the agencies that operated the Edward Jones Dome, but a judge dismissed them from liability last week, ruling that the team had full control of operations on game days.
The Rams no longer play in the stadium, as they moved to Los Angeles following the 2015 season.
Bush returned to the field in 2016 but finished the season with negative-three rushing yards on 12 carries as a member of the Buffalo Bills. The 33-year-old didn't play in 2017 and officially retired in December.