The Arizona Supreme Court says the Legislature can't cut cost-of-living increases promised to state retirees.

The ruling released Thursday comes in a case brought after the Legislature cut the increases in 2011 for retirees in the state plan for judges and elected officials.

A Superior Court judge ruled in favor of retired judges after they sued, but the state appealed.

The Legislature cut the cost-of-living increases after the judges' retirement system lost money in the Great Recession and became badly underfunded. The retired judges argued the increases were a promised benefit and lower courts agreed.

The high court agreed the increases are part of a promised retirement benefit and are protected by the pension clause of the state Constitution. That clause bars "diminishing or impairing" public retirement benefits.