Mission Viejo-based nursing home operator Ensign Group Inc. has paid $48 million to settle a U.S. Department of Justice investigation stemming from a Medicare fraud lawsuit filed by two former workers.

Ensign paid the money in a single lump sum.

The company said in a release that it agreed to settle the case, which was filed in 2006, without any admission of wrongdoing in order to resolve the allegations and avoid protracted litigation.

The company’s stock is up 1% in trading today to a market value of $936 million.