A federal judge levied more than $19.4 million in damages against Renal Care Group, a Fresenius Medical Care subsidiary, for falsely billing the Medicare system from 1999 to 2005.

Fresenius, which has its North American headquarters in Waltham, Mass., acquired Nashville-based Renal Care Group for $3.5 billion in 2005. RCG provided dialysis services from more than 425 clinics.